A   DESCRIPTION 


MINERALS  OE  COMMERCIAL  VALUE 


BARR1NGER 


UNIVERSITY  OF  CALIFORNIA. 


FROM   THE    LIBRARY  OF 

DR.  JOSEPH   LECONTE. 

GIFT  OF  MRS.   LECONTE. 
No. 


• 

m 


Wit'n  the  Compliments  of 


BY    THE    SAME    AUTHOR. 


THE   LAW   OF   MINES  AND   MINING 

IN   THE 

UNITED   STATES. 

BY 

DANIEL    MOREAUX    BARRINGER  AND  JOHN    STOKES    ADAMS. 
1    Volume,    8vo.      Sheep,    $7.SO,  net. 


PUBLISHED  BY   LITTLE,    BROWN   &   COMPANY,    BOSTON. 


A     DESCRIPTION 


OF 


MINERALS    OF    COMMERCIAL    VALUE 

A  Practical  Reference-book  for  the  Miner,  Prospector,  and  Business  Man,  or 

any  Person  who  may  be  interested  in  the  Extraction  or    Treatment 

of  the    Various  Metallic  or  Non-metallic  Minerals,  and  for 

Students  either  in  Field-work  or  in  the  Laboratory. 

BY 

D.    M.    BARRINGER,   A.M.,   LL.B., 

One  of  the  Authors  of  "  The  Law  of  Mines  and  Mining  in  the   United  States." 


FIRST   EDITION. 
FIRST    THOUSAND. 


NEW   YORK: 

JOHN   WILEY   &    SONS. 

LONDON  :   CHAPMAN  &  HALL,  LIMITED. 

1897. 


Copyright,  1897, 

BY 

D.   M.   BARRINGER. 


ROBERT   DRUMMOND,    BLECTROTYPBR    AND    PR1NTKR,    NEW    YORK. 


PREFACE. 


IN  the  preparation  of  this  little  book  the  original  intention  of  the  author  was  to  give  in  as  simple  and  concise  a  form  as 
possible  a  description  of  the  nature  of  only  the  more  important  of  those  mineral  substances,  more  frequently  referred  to  as  ores 
or  compounds,  which  possess  commercial  value,  indicating  at  the  same  time  the  means  by  which  they  could  be  identified,  and  refer- 
ring very  briefly  to  some  of  the  principal  economic  uses  to  which  they  are  put.  Upon  reflection,  however,  it  seemed  advisable  not 
to  confine  the  work  too  strictly  within  this  limitation,  but  to  insert  also  a  description  of  a  few  other  minerals  which  are  very  fre- 
quently met  with  as  common  veinstones  (i.e.,  gangue  of  the  metallic  ores)  or  as  rock  constituents,  although  they  may  possess  in 
themselves  little  or  no  commercial  worth.  Outside  of  this  he  has  not  attempted  to  go,  for  by  so  doing  he  would  be  defeating 
the  object  he  has  had  in  mind,  namely,  to  carefully  exclude  all  minerals  which  do  not  fall  under  either  of  the  above  classifications 
— by  far  the  greater  number — and  to  thus  confine  himself  to  a  brief  working  description  of  those  which,  for  the  reasons  given,  are 
directly  or  indirectly  useful. 

The  work  is  intended  merely  as  a  book  of  reference  to  be  used  by  the  practical  miner  or  man  of  business,  for  whom  espe- 
cially it  is  intended,  as  well  as  by  the  geologist,  metallurgist,  or  mineralogist,  in  so  far  as  it  may  serve  their  purposes.  If  the 
desired  mineral  be  not  enumerated  in  the  following  pages,  or  the  information  concerning  it  be  not  sufficiently  complete,  reference 

loiioo 


must  be  had  to  some  of  the  many  excellent  and  much  more  comprehensive  works  upon  mineralogy  by  such  well-known  authors  a£ 
Dana,  Brush,  Erni,  von  Kobell,  Rutley,  etc.,  from  which  this  little  volume  has  been  very  largely  compiled.* 

In  the  arrangement  of  the  material — that  is,  the  grouping  of  the  various  ores  or  compounds  under  the  element  for  the 
extraction  of  which  they  are  chiefly  mined — the  author  has  adopted  the  simplest  and  most  logical  form  which  has  occurred  to 
him,  and  he  hopes  that  it  will  meet  with  the  approbation  of  the  majority  of  those  who  may  have  occasion  to  refer  to  the  following 
pages. 

D.  M.  BARRINGER. 

BULLITT  BUILDING,  PHILADELPHIA,  June,  1897. 


*  For  fuller  information  concerning  any  mineral,  its  economic  uses  or  mode  of  occurrence,  the  two  following  most  excellent  and  modern  works  should  be 
consulted  :  Dana's  System  of  Mineralogy  (1897),  and  Rothwell's  Mineral  Industry  (in  five  volumes,  1892-1895).  The  latter  work  contains  much  very  useful 
information  concerning  the  occurrence,  production,  and  uses  of  the  various  minerals  of  economic  importance.  The  author  wishes  to  acknowledge  his  indebted- 
ness to  the  authors  of  ihe  above  books,  from  which  a  very  considerable  portion  of  the  information  herein  contained  has  been  derived.  See  also  the  Geological 
Preface  to  The  Law  of  Mines  and  Mining  in  the  United  States  (Barringer  and  Adams,  1897,  published  by  Little,  Brown  &  Co.  of  Boston),  by  the  author  of  this 
work,  which  contains  a  detailed  description  ot  the  various  kinds  of  ore  deposits  and  their  mode  of  occurrence  in  nature. 


A  DESCRIPTION 

OF 

MINERALS  OF  COMMERCIAL  VALUE, 


CONTENTS. 


PART  I.  PART  II. 

I.— SYMBOLS  AND  ATOMIC  WEIGHTS  OF  THE  ELEMENTS.        I.— TABLES  OF  MINERALS. 

II.— SYSTEMS  OF  CRYSTALLIZATION.  II.— CLASSIFICATION  OF  MINERALS. 

III.— SCALE  OF  HARDNESS  III.— APPENDIX. 

IV.— SCALE  OF  FUSIBILITY.  IV.— INDEX  TO  TABLES. 

V.— CHIEF  DIVISIONS. 


PART 

l.-SYMBOLS  AND  ATOMIC  WEIGHTS 


NAME. 

SYMBOL. 

AT.    WT. 

(approx.). 

NAME. 

SYMBOL. 

AT.    WT. 

(approx.}. 

Al 

27 

Di 

T/12  .  H 

Sb 

iTQ.  e. 

Eb 

l66 

Ar 

IQ.8  (?) 

F 

IQ 

As 

7"» 

Ga 

7O 

Ba 

137 

Ge 

T\  •  1 

Be 

Au 

TQ7 

Bi 

2O7.  ? 

H 

I 

B 

j  i 

In 

i  n  .  ^ 

Br 

80 

I 

126.5 

Cd 

112 

Ir 

IQ2.  f> 

Cs 

iao.  7 

Fe 

56 

Ca 

4O 

La 

1^8.  f, 

c 

12 

Pb 

206.  5 

Ce 

I4O 

Li 

7 

Chlorine  

Cl 

•7C.  e 

Magnesium  

Me 

24 

Cr 

C2 

Mn 

55 

Cobalt  

Co 

eg.  7 

He 

200 

Copper  (Cuprum)  

Cu 

61 

II.— SYSTEMS  OF  CRYSTALLIZATION. 

1.  Isometric  (e.g.,  cube  and  octahedron). — Three  axes  rectangular  in  intersections  and  equal. 

2.  Tetragonal  (e.g.,    right  prism  with   square   base). — Three  axes   rectangular  in   intersections — two  lateral   axes   ecjual  and 
unequal  to  the  vertical,  which  may  be  longer  or  shorter. 

3.  Hexagonal  (e.g  ,   rhombohedron   and   hexagonal   prism).  —  The   vertical   axis,  which   may   be   longer  or   shorter  than  tho 
lateral,  is  at  right  angles  to  them;  the  lateral,  which  are  equal,  are  three  in  number  and  intersect  at  angles  of  60°. 

6 


I. 


OF  THE  ELEMENTS. 


NAME. 

SYMBOL. 

AT.    WT. 

(approx.). 

NAME. 

SYMBOL. 

AT.    WT. 

(appro*.). 

Molybdenum  

Mo 
Ni 
Nb 
N 
Os 
O 
Pd 
P 
Pt 
K 
Rh 
Rb 
Ru 
Sa 
Sc 
Se 
Si 

•   96 
58-5 

93-7 
14 
191 
16 
106.3 
3i 
194-5 
39 
104 
85.2 
101.5 
149.6 
44 
79 
28 

Ag 
Na 
Sr 
S 
Ta 
Te 
Tl 
Th 
Sn 
Ti 
W 
Ur 
V 
Yb 
Yt 
Zn 
Zr 

107-5 
23 
87-5 
32 
182 
127.6 
203.6 
232 

"7-5 

48 

183-5 
240 

5i 
172.6 

89-5 
65 
90-5 

Nickel  

Strontium  

Oxv<ren  .  . 

Palladium  

Thallium  

Platinum  

Rhodium  

Ruthenium  

Vanadium  

Samarium  

Yttrium  

4.  Orthorhombic  (e.g.,  right  prism  with  rectangular  or  rhombic  base). — The  three  axes  rectangular  in  intersections  and  unequal. 

5.  Monoclinic  (e.g. ,  right   rhomboidal  and  oblique  rhombic  prisms). — Only  one  oblique    inclination  (one  lateral  axis  inclined 
to  the  vertical)  out  of  the  three  made  by  the  intersecting  axes,  two  being  rectangular;  the  three  axes  are  unequal. 

6.  Triclinic  (e.g.,  oblique  asymmetric  rhomboidal  prisms). — All  three  axes  unequal  and  their  intersections  are  all  oblique. 

UK-SCALE  OF   HARDNESS. 


i.   Talc. 

6.   Feldspar. 


2.  Gypsum,  Rock  Salt. 
7.  Quartz. 


3.  Calcite. 
8.  Topaz. 

7 


4.   Fluorite. 

9.   Corundum,  Sapphire. 


5.  Apatite. 
10.  Diamond. 


1V.-SCALE  OF  FUSIBILTY. 

I.  Stibnite.  2.  Natrolite.  3.  Alumina-iron  Garnet.  4.  Actinolite.  5.  Orthoclase.  6.  Bronzite. 

V.— CHIEF  DIVISIONS. 

1. 
ALUMINUM  AND  ITS  COMPOUNDS. 

Heated  on  charcoal  or  in  forceps  in  O.  F.  with  cobalt  nitrate  and  reheated  gives  a  blue  color.  A  blue  infusible  mass  only 
indicates  alumina.  (See  Heating  with  Cobalt  Nitrate  in  Appendix.) 

2. 

ANTIMONY  AND  ITS  COMPOUNDS. 

When  strongly  heated  in  closed  tube  yields  a  sublimate  near  assay  which  .s  black  when  hot  and  brown-red  when  coM. 
Characteristic  dense  white  fumes.  On  charcoal  white  sublimate  near  assay,  bluish  distant  from  assay  ;  crystals  in  coating  far  from 
assay  are  octahedrons  ;  those  near  assay  needlelike  (use  lens).  Sublimate  less  volatile  than  that  of  arsenious  acid.  H2S  passed 
through  acidified  antimonial  solution  gives  orange  precipitate.  Dissolved  in  aqua  regia  or  hot  H2SO4.  When  native  takes  fire 
and  continues  to  burn  without  further  heating,  and  becomes  covered  with  white  needles  of  antimony  oxide. 

3. 
ARSENIC  AND  ITS  COMPOUNDS. 

Heated  on  charcoal  volatilizes  with  white  incrustation,  which  is  deposited  far  from  assay,  and  which  is  easily  driven  off 
by  the  flame.  When  abundant  easily  recognized  by  garlic  odor  of  the  fumes.  In  closed  tube  gives  brilliant  black  sublimate  near 
assay  with  alliaceous  fumes.  When  flame  is  applied  to  this  sublimate  it  volatilizes,  and  the  characteristic  brilliant  but  minute 
octahedral  crystals  of  oxide  of  arsenic  are  deposited  further  up  the  tube. 

8 


4. 
BISMUTH  AND  ITS  COMPOUNDS. 

Its  presence  is  detected  by  characteristic  lemon  or  orange  sublimate,  which  it  and  its  compounds  give  when  treated  alone 
or  with  soda  on  charcoal  before  blowpipe.  With  sulphur  and  potassium  iodide  gives  a  scarlet  coating  far  from  the  assay.  Readily 
dissolved  by  nitric  acid,  which  solution  when  concentrated  gives  white  precipitate  when  poured  into  excess  of  water.  The  ores 
are  rare. 

5. 

CALCIUM  AND  ITS  COMPOUNDS. 

The  presence  of  calcium  may  be  often  detected  by  the  fine  orange-red  color  which  its  compounds  impart  to  blowpipe  flame. 
Best,  however,  to  test  for  it  in  the  liquid  way.  Carbonate  of  ammonium  produces  in  neutral  calcium  solutions  a  white  precipitate 
(CaCO3)  which  is  soluble  in  acids  with  effervescence  (CO2). 

6. 
CHLORINE. 

This  element,  though  not  occurring  in  a  free  state  in  nature,  is  largely  used  and  frequently  met  with  through 
the  many  compounds  which  it  forms,  such  as  chloride  of  ammonium,  copper,  mercury,  potassium,  sodium,  tin,  silver,  etc., 
which  see. 

Chlorides  when  heated  with  strong  sulphuric  acid,  save  those  of  mercury,  silver,  and  tin,  evolve  hydrochloric-acid  gas, 
known  by  its  pungent  smell  and  acid  reaction.  When  heated  with  peroxide  of  manganese  and  sulphuric  acid  chlorine  gas  is 
given  off,  recognizable  by  its  irritant  odor,  green  color,  power  of  bleaching  litmus,  etc.,  and  by  the  purple  stain  it  produces  on  a  piece 
of  starch-paper  moistened  with  iodide  of  potassium.  When  fused  with  a  little  carbonate  of  sodium  and  red  chromate  of  potassium 
they  furnish  a  mass  which,  when  warmed  with  strong  sulphuric  acid,  gives  off  deep  red  vapors  of  chromic  chloride,  CrOCl2 , 
decomposable  by  water  to  furnish  an  orange  solution  of  mixed  chromic  and  hydrochloric  acids,  becoming,  not  colorless,  but  only 
yellow,  when  rendered  ammoniacal.  (Odling.)  Fused  in  a  bead  of  microcosmic  salt  saturated  with  CuO  imparts  an  azure-blue 
color  to  flame. 

9 


7. 
CHROMIUM  AND  ITS  COMPOUNDS. 

Exists  chiefly  in  two  native  compounds,  viz.,  crocoite  (Siberia)  or  chromate  of  lead,  and  chromite  or  oxide  of  chromium  and 
iron.  It  is,  when  reduced  to  metallic  state,  a  whitish,  brittle,  and  very  infusible  metal.  Chief  source  is  chromite,  which  is  slightly 
magnetic.  Fuses  slightly,  is  soluble,  and  imparts  a  beautiful  emerald-green  color  to  beads  of  borax  and  salt  of  phosphorus  when 
cold. 

8. 
COALS. 

These  may  be  generally  easily  recognized  by  their  physical  characters,  which  are  too  well  known  to  require  description. 
"  It  passes  from  forms  which  still  retain  the  original  structure  of  the  wood  (peat,  lignite},  and  through  those  with  less  of  volatile 
or  bituminous  matter  to  anthracite,  and  further  to  kinds  which  approach  graphite  "  (Dana).  Each  species  gives  variable  analyses 
according  to  amount  of  impurities  present,  etc.,  etc. 

NOTE. — A  coking  coal  is  a  bituminous  coal  which  softens  or  becomes  pasty  or  semi-viscid  in  the  fire.  This  is  attended 
with  escape  of  bubbles  of  gas.  The  volatile  products  resulting  from  the  decomposition  of  the  softened  mass  being  driven  off,  a 
more  or  less  coherent,  grayish-black,  cellular,  or  fritted  mass  is  left,  which  is  coke,  or  the  part  not  volatile,  and  which  varies  from 
50  to  85  per  cent.  A  non-coking,  free-burning  coal  may  be  like  the  former  in  all  external  characteristics,  and  even  in  percentage  of 
volatile  matter  and  in  general  composition,  but  it  burns  freely  without  softening  or  any  appearance  of  incipient  fusion.  The 
coke  resulting  from  this  is  not  a  proper  coke,  being  often  in  a  powder  or  in  the  form  of  the  original  coal.  (Dana.) 

9. 
COBALT  AND  ITS  COMPOUNDS. 

Easily  recognized  by  the  characteristic  deep  sapphire-blue  bead  in  both  flames  with  borax  or  salt  of  phosphorus.  The 
sulphurets  should  be  roasted  on  charcoal  before  testing  with  borax,  as  in  other  metallic  species.  Dissolves  in  nitric  acid.  The 
insolubility  of  the  black  sulphides  of  nickel  and  cobalt  in  dilute  HC1  suffices  to  separate  these  metals  from  the  remaining  members 
of  the  group.  If  ferrocyanide  of  potassium  be  added  to  solution,  first  made  freely  ammoniacal,  a  green  precipitate  is  produced. 

10 


If  ferrocyanide  be  added,  the  precipitate  is  brown-red.  (Do  not  confound  with  similar  precipitate  of  copper.)  Sometimes  associ- 
ated with  oxides  of  manganese.  (Missouri  and  South  Carolina.)  Largely  associated  with  arsenic,  but  the  blue  color  of  bead 
suffices  to  readily  distinguish  them  from  arsenopyrite. 

10. 
COPPER  AND  ITS  COMPOUNDS. 

Borax  bead  in  O.  F.  is  green  when  hot,  and  greenish-blue  when  cold  ;  in  R.  F.  colorless  if  saturation  be  weak,  but  red 
with  strong  saturation  when  hot  ;  metallic  copper  and  copper-red  when  cold.  On  charcoal  with  soda  a  copper-colored  globule  is 
obtained.  When  combined  with  the  oxides,  tin  and  borax  should  be  used.  When  ammonia  in  excess  is  added  to  nitric  acid  solu- 
tion, the  liquid  is  colored  blue  ;  metallic  copper  is  deposited  on  iron  wire  or  a  nail  immersed  in  this.  Specimens  should  be  roasted 
before  making  B.  B.  test  with  borax.  For  traces  of  copper  place  drop  of  suspected  solution  on  platinum  foil.  Place  in  this  a 
piece  of  zinc  ;  a  film  of  copper  will  be  deposited  on  the  platinum  foil  at  point  of  contact.  Copper  compounds  moistened  -vith  a 
drop  of  HC1  and  ignited  B.  B.  color  the  flame  azure-blue. 

11. 
GOLD  AND  ITS  COMPOUNDS. 

Gold  may  be  generally  recognized  by  its  physical  characters — color,  lustre,  malleability,  and  specific  gravity.  When  a 
gold  compound  is  heated  on  a  carbonized  match  or  charcoal  in  R.  F.,  a  yellow  malleable  bead  is  obtained  which  dissolves  in  aqua 
regia.  If  this  solution  be  dropped  on  to  a  filter-paper,  and  one  drop  of  stannous  chloride  be  added,  a  purple-red  color  is  obtained. 
Gold  can  be  readily  detected  in  its  solutions,  inasmuch  as  it  is  obtained  in  a  metallic  state  by  reducing  agents.  The  well-washed 
precipitate  being  dissolved  and  tested  with  stannous  chloride,  it  is  separated  from  the  easily  volatile  metals  by  simply  heating  on 
charcoal  in  O.  F.  If  associated  with  copper  or  silver,  it  must  be  fused  with  a  large  excess  of  pure  metallic  lead  and  subjected  to 
cupellation.  The  copper  is  absorbed  into  the  cupel  with  the  lead,  while  the  silver  remains  alloyed  with  the  gold.  If  the  globule 
is  quite  yellow,  this  is  a  proof  that  but  little  silver  is  present.  It  is  then  to  be  tested  with  salt  of  phosphorus  to  prove  the  presence 
of  silver,  which,  after  fusing  on  charcoal  in  O.  F.,  will  impart  an  opaline  character  to  the  cool  bead.  If  it  be  more  of  a  silver- 
white  color,  the  amount  of  gold  will  be  small  ;  and  in  order  to  prove  its  presence  and  approximate  quantity,  the  globule  must  be 
digested  with  nitric  acid  by  application  of  heat.  The  silver  is  thus  dissolved,  and  the  gold  remains  as  a  dark  powder  or  spongy 
mass.  If  this  powder  or  mass  be  washed  and  fused  with  borax  on  charcoal,  it  will  yield  a  globule  of  metallic  gold, 

11 


12. 
HYDROCARBONS. 

Compounds  of  carbon,  hydrogen,  and  oxygen.  These  compounds  are  numerous,  and  form  a  great  variety  of  economically 
important  gaseous,  liquid,  and  solid  products,  the  composition  and  characters  of  the  more  prominent  among  which  are  stated  under 
their  proper  heads.  For  sake  of  distinguishing  between  them  the  various  coals  are  placed  in  a  separate  division,  although  they 
are  also  oxygenated  hydrocarbons — one  point  of  difference  being  that  the  substances  here  enumerated  generally  yield  large  quanti- 
ties of  paraffine,  while  this  can  be  said  of  only  few  of  the  coals.  While  the  latter  chemically  considered  possess  many  character- 
istics in  common  with,  they  differ  widely  in  physical  and  in  other  respects  from,  the  varieties  enumerated  in  the  tables  under  this 
division. 

13. 

IRON  AND  ITS  COMPOUNDS. 

With  borax  in  O.  F.  oxide  of  iron  gives  a  dark  brown-red  glass,  which  becomes  pale-yellowish  or  colorless  on  cooling  ;  in 
R.  F.  bottle-green  on  cooling.  With  tin  the  green  color  is  hastened.  Most  of  the  compounds  become  magnetic  when  heated  with 
soda  on  charcoal.  Dissolve  readily  in  HC1.  Sulphide  of  ammonium  gives  to  their  solution  a  black  precipitate,  which  is  soluble 
in  dilute  HC1,  distinguishing  it  from  cobalt  and  nickel.  Another  excellent  test  is  to  add  ferrocyanide  of  potassium  to  solution. 
A  pale-blue  precipitate  indicates  ferrous  salts,  and  a  dark-blue  precipitate  ferric  salts,  of  iron.  The  presence  of  titanium  may  be 
detected  by  the  fact  that  the  borax  or  salt  of  phosphorus  bead  becomes  violet-blue  or  reddish  purple  when  the  R.  F.  is  directed 
upon  it,  especially  if  tin  be  added,  and  test  made  on  charcoal.  A  better  test  is  to  add  tin  to  concentrated  HC1  solution,  and 
continue  to  boil.  Set  aside.  If  titanium  is  present,  the  solution  becomes  violet  in  color.  The  presence  of  chromium  is  also 
readily  detected.  (See  Chromic  Iron.) 

14. 
LEAD  AND  ITS  COMPOUNDS. 

They  are  easily  fusible.  With  borax  bead  and  with  soda,  ana  olten  alone,  on  charcoal,  a  malleable  bead  may  be  obtained. 
Readily  recognized  by  characteristic  lemon-  or  sulphur  yellow  coating  near  assay  when  cold  ;  red  when  hot.  The  outer  coating  is 


faintly  bluish  white  when  cold.  When  S  and  KI  are  added  there  is  a  greenish-yellow  coating  far  from  assay.  Sublimes  readily. 
Volatile,  tinging  flames  azure-blue.  In  nitric-acid  solution  of  salts  of  lead  sulphuric  acid  gives  a  white  precipitate,  which  is  nearly 
insoluble  in  water  and  dilute  acids.  Heated  in  open  tube  white  smoke  and  a  non-volatile  fusible  sublimate  is  deposited  on  under 
side  of  tube.  Oxides,  carbonates,  etc.,  may  be  reduced  to  the  metallic  state  by  heating  in  R.  F.  with  soda,  and  the  characteristic 
coating  will  be  produced  on  the  coal.  But  sulphides,  arsenides,  etc.,  of  lead  must  be  treated  in  O.  F.  to  produce  the  metal. 
Metallic  lead  obtained  as  above  may  be  cupelled  for  silver  on  charcoal,  or,  better,  on  a  bone-ash  cupel.  (See  B.  B.  Silver  Assay, 
Appendix.) 

• 
15. 

MAGNESIUM  AND  ITS  COMPOUNDS. 

These  afford  a  clear  rose-red  or  pink  color  with  cobalt  nitrate  after  long  heating.  This  distinguishes  it  from  alumina. 
Distinguished  from  strontia  and  baryta  by  different  flame-colors,  and  in  the  wet  way  by  the  fact  that  sulphuric  acid  gives  no 
precipitate  in  dilute  HC1  solution.  The  fact  that  the  precipitate  from  magnesia  is  soluble  in  water,  while  that  from  calcium  is 
not,  suffices  to  distinguish  it  from  the  latter,  etc. 

16. 

MANGANESE  AND  ITS  COMPOUNDS. 

These  are  readily  recognized  by  the  characteristic  amethystine  color  oxide  of  manganese  imparts  to  beads  of  borax  and 
salt  of  phosphorus  in  O.  F. ;  colorless  in  R.  F.  With  borax  the  color  becomes  violet,  amethystine,  or  purple  when  hot  ;  amethys- 
tine when  cold.  With  salt  of  phosphorus,  brown-violet  when  hot  ;  pale  red-violet  when  cold.  Do  not  confuse  with  pale  violet 
color  imparted  to  beads  by  presence  of  titanic  acid,  which  only  appears  on  heating  in  R.  F.  Too  large  a  quantity  renders  bead 
opaque.  With  soda  in  O.  F.  on  platinum  wire  or,  preferably,  platinum  foil,  the  color  is  green  or  bluish  green.  Most  varieties  are 
soluble  in  hydrochloric  acid  with  evolution  of  chlorine.  The  oxides  are  frequently  associated  with  ores  of  iron,  especially  brown 
hematite  (limonite),  and  less  often  with  varieties  of  red  hematite  or  magnetite 

13 


It. 

MERCURY  AND  ITS  COMPOUNDS. 

Mercury  and  amalgams  volatilize  on  charcoal,  but  give  a  sublimate  of  metallic  mercury  when  heated  in  closed  tube  with 
or  without  soda  ;  best  with  soda.  The  metal  condenses  above  assay  in  globules  on  the  tube.  These  may  be  brushed  together 
with  a  feather,  etc.  When  a  gray  sublimate  is  obtained  without  distinct  metallic  globules,  the  part  of  the  tube  coated  with  it  is 
cut  off  and  boiled  in  a  test-tube  with  a  little  dilute  HC1.  By  this  treatment  mercury  collects  in  shining  globules.  In  case  mer- 
cury exists  in  so  small  a  quantity  that  the  sublimed  metal  is  not  perceptible,  it  may  be  detected  by  inserting  a  piece  of  gold-leaf 
held  on  end  of  iron  wire  into  the  tube  just  above  assay.  On  heating  the  mercury  is  volatilized  and  unites  with  the  gold,  giving  it 
a  wnite  color. 

18. 
MOLYBDENUM  AND  ITS  COMPOUNDS. 

With  borax  bead  in  O.  F.  colorless  when  hot  ;  faint  yellow  when  cold.  With  saturation  the  bead  becomes  in  R.  F.  an 
opaque  black  or  bluish  to  green  enamel  when  cold. 

19. 

NICKEL  AND  ITS  COMPOUNDS. 

With  borax  the  presence  of  nickel  in  O.  F.  renders  bead,  when  hot,  purplish,  with  tinge  of  violet  ;  when  cold,  reddish 
sherry-brown.  In  R.  F.  the  bead  becomes  purplish  gray  and  turbid,  with  reduced  nickel  (use  lens).  If  a  fragment  of  nitre  be 
added  and  the  bead  be  again  heated  in  O.  F.,a  well-marked  purple  color  is  produced.  Roast  before  making  above  tests.  Arseni- 
cal compounds  of  nickel,  cobalt,  iron,  and  copper  are  treated  with  glass  of  borax  (see  Cobalt)  ;  when  borax  is  no  longer  colored 
blue  from  cobalt,  but  acquires  a  brown  color,  which  is  violet  when  hot,  the  metallic  globule  is  separated  from  the  borax  and  treated 
with  salt  of  phosphorus  in  O.  F.  If  copper,  as  well  as  nickel,  be  present  in  the  assay,  the  glass  thus  obtained  will  be  green  while 
both  hot  and  cold.  Treated  with  tin  on  charcoal  it  will  become  red  and  opaque  on  cooling.  Black  sulphides  insoluble  in  dilute 
HC1.  (See  Cobalt.)  Nitric  solutions  are  apple-green.  Excess  of  ammonia  produces  a  violet-blue  liquid,  from  which  caustic 
potash  slowly  precipitates  the  green  hydrate  of  nickel.  Potash  produces  this  precipitate  from  all  ordinary  nickel  solutions. 

14 


20. 
PHOSPHATE  ROCK. 

Mineral  variety,  apatite,  which  see.  Common  variety,  often  replacement  of  CaCO3  by  phosphate  of  lime  ;  also  includes 
fossil  teeth,  bones,  etc.  The  substance  examined  for  phosphorus  is  mixed  with  soda,  as  for  sulphur  (3  soda,  i  substance).  A 
thin  glass  tube  closed  at  one  end  has  a  piece  of  magnesium  wire  or  ribbon,  one-half  inch  long,  dropped  into  it.  Then  the  mixed 
soda  and  substance  is  added  so  as  to  cover  the  magnesium.  Heat  to  fusion  the  contents  of  the  tube  until  the  glass  is  attacked. 
While  still  red  plunge  under  water  in  a  small  vessel,  and  immediately  apply  the  nose.  The  characteristic  odor  of  hydrogen  phos- 
phide is  evolved. 

Precautions. — Heat  to  full  fusion.  Do  not  have  too  much  water  in  vessel  ;  see  that  end  of  tube  is  broken.  The  above 
test  is  not  delicate  enough  for  minute  quantities,  as  in  Bessemer-iron  ores.  In  examining  iron  ores  for  phosphorus  try  to  find 
small  grains  of  apatite,  and  test  as  above.  Best  test  is  to  add  molybdate  of  ammonium  to  nitric-acid  solution.  An  abundant  bright 
yellow  precipitate  (phospho-molybdate  of  ammonium)  indicates  character  of  the  specimen. 

21. 
SILVER  AND  ITS  COMPOUNDS. 

Silver  compounds  when  fused  with  soda  on  charcoal  yield  a  hard,  white,  malleable  button,  usually  without  any  incrusta- 
tion on  the  coal,  but  when  treated  for  a  long  time  with  the  reducing  flame  a  slight  dark-red  coating  is  produced.  When  associated 
with  volatile  and  easily  oxidizable  metals  it  may  be  separated  by  heating  on  charcoal  in  O.  F.,  but  if  associated  with  large  quanti- 
ties of  lead  or  bismuth  it  is  best  to  subject  it  to  cupellation.  (See  Appendix.)  HC1  gives  in  a  solution  of  silver  a  white  heavy 
precipitate  of  AgCl,  which  is  insoluble  in  boiling  nitric  acid,  but  readily  soluble  in  ammonia.  The  color  of  the  precipitate  changes 
to  slate-purple  by  exposure  to  light.  This  is  a  distinguishing  characteristic. 

22. 

SULPHUR  AND  SULPHIDES. 

The  following  is  usually  sufficient  to  detect  the  presence  of  sulphur.  Mix  the  substances  suspected  to  contain  sulphur  with 
soda  (3  soda,  I  substance),  and  heat  on  platinum  wire  or  charcoal  in  R.  F.  The  fused  mass  is  then  crushed  on  a  clean  piece  of 

15 


silver  (coin  or  plate),  and  a  drop  of  water  added.  A  yellowish  stain  on  the  silver  indicates  a  trace  of  sulphur  ;  larger  quantities 
give  a  brown  or  a  black  stain.  Sulphides  such  as  pyrites,  galena,  etc.,  heated  on  charcoal  give  the  odor  of  burning  sulphur. 
Mixed  with  soda  as  above  and  heated  in  O.  F.  on  platinum  wire,  the  sulphides  color  the  coin  brown  to  black  ;  but  sulphates, 
gypsum,  baryta,  etc.,  so  treated  in  O.  F. ,  do  not  color  the  coin  ;  in  R,  F.,  however,  the  sulphate  is  changed  to  sulphide  and  colors 
the  coin.  Sulphides  or  substances  containing  sulphides  in  considerable  quantities  yield  sulphur  dioxide  when  heated  in  open 
tube.  The  sulphur  dioxide  may  be  recognized  by  its  odor  and  by  reddening,  and  sometimes  bleaching  blue  litmus-paper  inserted 
in  end  of  tube.  Usually  soluble  in  nitro-hydrochloric  or  concentrated  nitric  acid.  Some  are  extremely  difficult  to  dissolve  com- 
pletely, owing  to  the  deposition  of  sulphur,  which  fuses  around  the  unaltered  substance  and  prevents  any  action  of  the  acid 
upon  it,  but  these  can  usually  be  recognized  by  their  volatility,  etc.  (mercury,  arsenic,  etc.).  The  higher  sulphides  give  off  sulphur 
when  heated  in  closed  tube.  Free  sulphur  fuses  and  sublimes,  and  on  charcoal  burns  with  a  blue  flame,  and  affords  odor  of 
burning  sulphur. 

23. 

TELLURIUM  AND  ITS  COMPOUNDS. 

Of  no  use  in  the  arts.  Rarely  occurs  native,  when  it  is  a  white  and  brittle  metal,  which  is  easily  fusible,  with  greenish 
flame.  It  fumes  strongly,  and,  in  presence  of  selenium,  gives  the  peculiar  odor  of  decomposing  horse-radish.  Usually  combined 
with  the  other  metals  as  tellurides  of  gold,  silver,  lead,  and  bismuth,  which  see.  In  open  tube  a  white  or  grayish  sublimate  is 
obtained,  which  may  be  fused  to  clear,  colorless  drops.  Soluble  in  nitric  acid. 

24. 
TIN  AND  ITS  COMPOUNDS, 

Fused  with  soda  and  borax  on  charcoal  in  R.  F.,  the  compounds  of  tin  yield  a  globule  of  the  metal.  At  the  same  time  a 
coating  is  formed  on  the  coal  which  is  slightly  yellow  when  hot,  but  white  when  cold.  To  obtain  a  coating,  however,  the  assay 
must  be  kept  covered  with  the  blue  R.  F.  The  coating  moistened  with  cobalt  solution,  and  heated  in  the  O.  F.,  assumes  a  bluish- 
green  color.  Sulphides  should  always  be  roasted.  When  a  solution  of  salts  of  tin,  acidulated  with  HC1,  is  brought  in  contact 
with  metallic  zinc,  metallic  tin  is  thrown  down  in  the  form  of  scales  or  as  a  gray  spongy  mass. 

10 


25. 

TUNGSTEN  AND  ITS  COMPOUNDS. 

Before  blowpipe  compounds  of  tungsten  impart  to  salt-of-phospkorus  bead  at  first  a  dirty  green,  then  a  blue  color  when 
cold.  If  iron  is  present,  the  bead  appears  blood-red.  Best  with  tin  on  charcoal.  Characteristic  reaction  is  that  when  boiled 
with  phosphoric  acid  its  compounds  give  a  beautiful  blue  sirup.  Often  associated  with  tin  ores. 

26. 
ZINC  AND  ITS  COMPOUNDS. 

Compounds  of  zinc  with  borax  give  a  clear  glass,  which  is  milk-white  on  flaming,  or  with  more  assay  becomes  enamel- 
white  on  cooling.  In  the  R.  F.  on  charcoal  burns  with  a  greenish-blue  flame.  Fumes  are  given  off,  depositing  much  oxide,  which 
coating  is  yellow  when  hot,  but  white  when  cold.  With  soda  on  charcoal  the  ores,  even  when  containing  little  zinc,  afford  the 
peculiar  bluish  flame  of  burning  zinc,  and  the  oxide  is  deposited  on  the  coal.  When  this  coating  is  moistened  with  cobalt  nitrate, 
a  fine  yellowish  or  dirty-green  color  is  obtained  (either  alone  or  with  soda),  while  tin  gives  a  bluish-green  color  when  similarly 
treated. 

END  OF  PART  I. 


17 


PART   II. 

I.— TABLES. 


NAME. 


COMP.  AND 

PERCENTAGE 
OF  IMPORTANT 
CONSTITUENT. 


GENERAL  CHARACTERS  AND  ASSOCIATIONS. 


SPECIFIC 


BEFORE  BLOWPIPE. 


ALUMINUM  AND  ITS  COMPOUNDS. 

Heated  on  charcoal  or  forceps  in  O.  F.  with  cobalt  nitrate  and  reheated  gives  a  blue  color.  A  blue  infusible  mass  only 
Forms  many  useful  alloys,  e.g.,  aluminum  bronze  and  ferro-aluminum  in  making  and  casting  steel,  etc.  Many  articles  are  made  entirely 
forms,  suck  as  ingots,  sheets,  wire,  etc.  Its  ores,  especially  bauxite,  are  also  largely  used  for  the  manufacture  of  aluminum  salts  or 

The  ores      AlaOa,  Occurs  as  irregularly  round  concretions — rarely  amorphous.     Concretionary  structure  never  wholly  absent 

of  Alu-          H»O,  or  Pebble-like,  pisolitic,  oolitic,  vesicular,  and  amorphous.     Origin  ascribed  to  deposition  of  solutions  con- 

ininurn  AliiFeaOs  tained  in  waters  of  thermal  springs  and  geysers,  though  often  due  to  decay  of  certain  rocks,  and  found 

are:  +2HaO.  in  the  residual  clay.     Gives  much  water  in  closed   tube.     Common  impurities — silica,  iron,  and  titanic 

acid.     Other  accidental  impurities  are  phosphoric  acid,  sulphuric  acid,  carbonic  acid,  lime,  magnesia, 

Bauxite.  Aluminum  etc.  Presence  of  titanium  characteristic.  (Compare  kaolinite.)  Some  European  deposits  form  more  or 
less  stratified  beds,  but  the  Georgia  and  Alabama  deposits  are  superficial  and  pockety.  Deposits  in  these 
states  usually  occur  in  connection  with  Silurian  rocks  (dolomite),  but  supposed  to  have  been  formed  in 
Tertiary  times.  French  deposits  occur  in  connection  with  Cretaceous  limestone  and  are  interbedded 
with  lacustral  formations.  (See  i6th  An.  Rep.  U.  S.  Geol.  Sur.,  part  ill — Mineral  Resources,  1894,  p. 
547  et  seq.)  Frequently  associated  with  iron  ore  and  sometimes  mistaken  for  honeycombed  impure 
iron  ore. 


Cryolite. 


Ala03, 
H»O,  or 
Al»FeaO8 
+  2HaO. 

Variable. 

Aluminum 
from  20  to 

40*. 

sometimes 
much  more 

Na.Al,F,,. 

Aluminum 
12.8*. 

Sodium 

32.8*. 

Fluorine 

54-  4X- 


Easily  fusible  in  flame  of  candle.  Massive,  cleavable,  brittle, 
fracture  uneven.  Only  workable  quantities  known  in  Green- 
land. Said  to  be  found  there  in  a  large  vein  in  gneiss,  and  to 
be  associated  with  galena,  blende,  siderite,  cassiterite,  pyrites, 
fluor-spar,  etc.  Also  sparingly  in  quartz  veins  in  granite  in 
Colorado. 


,. 


the  forceps  fuses  easily,  coloring 
flame  yellow.  On  charcoal  fuses  to 
a  clear  bead  which  becomes  opaque 
on  cooling.  In  the  open  tube  when 
so  heated  that  the  flame  enters  the 
tube,  hydrofluoric  acid  is  driven  off, 
etching  the  glass. 


CHARACTERS. 

TREATMENT  WITH  ACIDS, ETC. 


COLOR. 


LUSTRE.       STREAK 


FUSI- 
BILITY. 


HARD- 
NESS. 


SP.  GR. 


CRYS- 
TALLI- 
ZATION. 


MAGNETIC 
BEFORE 

OR  AFTER 

HEATING. 


USES. 


indicates  alumina.     (See   Heating   with  Cobalt   Nitrate  in  Appendix.) USES.—  Of  rapidly  increasing  commercial  importance. 

from  it  where  light  weight,  durability,  and  non-liability  to  tarnish,  as  well  as  other  metallic  attributes,  are  desirable.     Made  into  many 


In  addition  to  being  used  as 
an  ore  of  aluminum,  it  is 
very  largely  used  in  the  man- 
ufacture of  alum,  for  which 
purpose  the  insoluble  matter 
should  not  exceed 7%,  nor  the 
oxide  of  iron  2.75^.  Also  usrtl 
in  the  manufacture  of  very 
high-grade  and  refractory 
crucibles  and  fire-brick. 


In  addition  to  being  to  a  lim- 
ited extent  an  ore  of  alumi- 
num, and  used  in  the  manu- 
facture of  alums,  cryolite 
is  used  in  the  manufacture 
of  a  porcelain-like  glass.  It 
is  also  used  in  the  manu- 
facture of  chemically  pure 
soda. 


compounds,  especially  alu 

ms. 

"      ' 

•    . 

HC1  affects  it  but  little, 

White, 

Dull.  • 

'    .  '.    ' 
Earthy 

Infus. 

; 
Vari-          2.55 

, 
Usually      In 

while        concentrated 

brown,  and                           or            or            able.                                       slightly       a 

phosphoric    acid    dis- 

red to  black.                          like         above                                                     after.           % 

solves    it    almost   en- 

Also cream-                         color.      5.                                                                                 t 

tirely.       Soluble    also 

or  pearl-                                                                                                                                  p 

in  sulphuric  acid. 

white,  gray- 

s 

ish,  yellow- 

c 

ish,  amber, 

i 

pinkish. 

t 

Frequently 

c 

mottled  and 

, 

iron-stained 

I 

No  effervescence  when 

White,  red-       Vitre-         White, 

i 

2-5 

3 

V. 

i. 

heated  with  HC1.  Sol- 

dish to               ous  to         etc- 

i 

uble  in  sulphuric  acid 

brownish,          greasy. 

. 

B 

with  evolution  of  hy- 

and rarely 

f 

drofluoric  acid. 

black. 

i 

1 

.' 

c 

•        , 

.- 

i 
f 
s 

21 


NAMI 


Alum. 


COMP.  AND 

PERCENTAGE 
OF  IMPORTANT 
CONSTITUENT. 

Very  vari- 
able. 


GENERAL  CHARACTERS  AND  ASSOCIATIONS. 


The  alums  proper,  which  may  be  fibrous  or  massive  or  mealy  or  in 
solid  crusts,  are  hydrous  sulphates  of  alumina  with  an  alkali  metal 
and  24  molecules  of  water.  Thus  potash  alum  (kalinite)  has 
formula  KaSO4AU(SO4)i  -f-  24HaO,  while  soda  alum  (mendozite) 
has  formula  Na»SO4,  Alj(SO«)s+24H2O.  That  is  to  say,  the  former 
contains  sulphur  trioxide,  33.7;  alumina,  10.8;  potash,  9.9;  water, 
45.6;  and  the  latter  contains  sulphur  trioxide,  34.9;  alumina,  n.i; 
soda,  6.8;  water,  47.2.  The  former  is  much  more  common.  Alum 
effloresces  on  argillaceous  minerals  and  particularly  alum  shales. 
More  or  less  common.  A  more  or  less  common  variety  is  halo~ 
trichite,or  iron  alum,  where  either  magnesium,  iron,  manganese, 
etc.,  are  present;  e.g.,  samples  from  New  Mexico  contain  sulphur 
trioxide,  37.19;  alumina,  7.27;  iron  protoxide,  13.59;  insoluble, 
0.50.  (Dana.) 

NOTE. — Ammonia  alum  (comparatively  rare  in  nature)  is  now  ex- 
tensively manufactured  from  the  waste  of  gas-works,  and  is  used 
in  the  place  of  potash  alum. 


^______       BEFORE  BLOWPIPE. 

Generally  fuses  in  its  own  water  of 
crystallization  and  froths,  forming 
a  spongy  mass.  Intense  blue  when 
moistened  with  cobalt  solution.  On 
charcoal  forms  a  hepatic  mass. 


ANTIMONY  AND  ITS  COMPOUNDS. 

Native        Sb.  When  strongly  heated  in  closed  tube  yields  a  sublimate  near  assay,  which  is  black  when  hot  and 

(rare).  crystals  in  coating  far  from  assay  are  octahedrons;  those  near  assay  needle-like  (use  lens).     Sublimate 

in  aqua  regia  or  hot  HjSOi.     When  native  takes  fire  and  continues  to    burn   without   further  heating, 
in  general  rendering  metals  more  lustrous,  hard,  and  brittle.      When  alloyed  with  lead  it  is  largely  used  in  the 
to  a  small  extent  in  medicine.     Alloyed  with  lead  it  is  also  used  in  alkali-works  f»r  making  pumps  and  taps  for 
Sometimes  occurs  in   nature  alloyed  with   other  metals,  such  as 
arsenic,  silver,  and  nickel. 


CHARACTERS. 

COLOR.              LUSTRE. 

STREAK 

FUSI- 
BILITY. 

HARD- 
NESS. 

SP.  GR. 

CRYS- 
TALLI- 

MAGNETIC 

BEFORE 
OR  AFTER 

TREATMENT  WITH  ACIDS,ETC. 

I 

ZATION. 

HEATING. 

Generally  soluble  in  20 

Generally         Vitreous 

White 

Easily 

2-3 

1-75- 

I,  also 

Us 

times    its    weight    of 

white  to           to  silky. 

1.90 

V  and 

pa 

cold  water,  and  very 

yellowish        Trans- 

VI. 

de 

much   less  in  boiling 

white,              parent 

ar 

water. 

and 

tu 

translu- 

m 

cent,  but 

ca 

varie- 

P< 

ties  be- 

th 

come 

ca 

dull  on 

expos- 

/ 

ure. 

USES. 


Used  in  the  manufacture  of 
paper,  dyes, andbaking-pow- 
ders;  also  in  tanning  leather, 
and  in  clarifying  or  filtering 
turbid  or  impure  water.  Alu- 
minate  of  sodium  is  used  in 
calico-printing  and  the  sa- 
ponification  of  fats,  and  in 
the  manufacture  of  stearine 
candles,  etc. 


brown-red  when  cold.     Characteristic  dense  white  fumes.     On  charcoal  white  sublimate  near  assay,  bluish  distant  from  assay; 
less  volatile  than  that  of  arsenious  acid.     H2S  passed  through  acidified  antimonial  solution  gives  orange  precipitate.     Dissolved 

and  becomes  covered  with  white  needles  of  antimony  oxide. USES. — Its  chief  use  is  as  an  alloy  with  other  metals,  an  admixture 

manufacture  of  type-metal.     It  also  forms  part  of  the  anti-friction  metals,  such  as  babbitt  metal,  employed  for  bearings  in  machinery,  and 
raising  and  drawing  off  acids. 


NAME. 


COMP.  AND 

PERCENTAGE 
OF  IMPORTANT 
CONSTITUENT. 


ANTIMONY  AND 

Stibnite.       SbaS». 
(Anti- 
mony Antimony, 
Glance).  71-4*- 
The  oth- 
er ores 
are  com- 
parately 
rare. 


GENERAL  CHARACTERS  AND  ASSOCIATIONS. 


ITS  COMPOUNDS.— Continued. 

Burns  in  flame  of  candle.  Slightly  sectile.  Almost  the  entire 
supply  of  commerce  is  derived  from  this  ore. 

Usually  associated  with  silver,  lead,  copper,  etc.,  in  many  veins 
and  other  classes  of  deposits  in  which  the  ores  of  these  metals 
occur.  Frequently  met  with  throughout  the  Rocky  Mountain 
region.  Occurs  with  quartz  in  veins  in  clay-slate  in  Arkansas, 
but,  like  the  other  ores  with  which  it  is  found,  occurs  in  many 
kinds  of  rock. 


SPECIFIC 


BEFORE  BLOWPIPE. 


Volatilizes  and  gives  off  white  fumes 
and  a  sulphurous  odor.  Fuses 
easily  and  colors  flame  greenish 
blue.  On  charcoal  fuses  and  gives 
white  coating  which  volatilizes 
when  R.  F.  is  turned  upon  it,  color- 
ing flame  green-blue. 


Cervan- 
tite 
(Ker 
mesite) 
(SbaOSa) 
is  cher- 
ry-red 
variety. 

(White 
anti- 
mony) 
Valen- 
tinite. 


SbaO4. 
Antimony, 


SbaOs. 
Antimony, 


Antimony  oxide  resulting  from  decomposition  of  stibnite  and  other     Infusible,  but  easily  reduced  on  char- 
ores  of  antimony.  coal. 


Becomes   yellow   in  flame  of  candle   and   fuses  to  a  white  mass.     Much  the  same  as  stibnite. 
Translucent  to  subtransparent. 


24 


CHARACTERS. 

TREATMENT  WITH  ACIDS, KTC. 


COLOR. 


LUSTRE.       STREAK 


FUSI- 
BILITY. 


HARD- 
NESS. 


SP.  GR. 


CRYS- 
TALLI- 
ZATION. 


MAGNETIC 

BEFORE 
OR  AFTER 

HEATING. 


USES,    j 


In  closed  tube,  black  to     Lead-gray  to     Metal- 

Gray 

i 

2 

4.5          IV.                         See  under  heading  ANTIMONY, 

brown  sublimatewhen       steel-gray.        lie  to 

and 

etc. 

hot,    which    becomes                                 splen- 

shin- 

brown-red on  cooling.                                  dent. 

ing 

Yellow   sublimate    of 

tar- 

sulphur further  up  the 

nish. 

tube.     When    pulver- 

Like 

ized  and  treated  with 

color. 

potassa  is  rapidly  col- 

ored ochre-yellow  and 

. 

mostly  dissolved.  Sol- 

uble   in   hydrochloric 

acid  when  pure. 

1 

Reacts    for   antimony.     Yellow, 

Pearly 

Yel-        Infu-         4.5         4.08         IV.                         See  under  heading  ANTIMONY, 

Soluble  in  HC1.                  white,  and        or 

lowish      sible.                                                                           etc. 

reddish              greasy, 

white 

white.                some- 

to 

times 

white 

earthy. 

Insoluble      in      water.     White,                Pearly 

White         i            2.5          5.57         IV.                         See  under  heading  ANTIMONY, 

Dissolves    readily   in      sometimes         or  ada- 

etc. 

HC1    without    evolu-      red  or  gray,      mantine 

tion  of  gas. 

NAME. 


COM  p.  AND 
PKRCENTAGK 
OF  IMPORTANT 
CONSTITUENT. 


GENERAL  CHARACTERS  AND  ASSOCIATIONS. 


SPECIFIC 


BEFORE  BLOWPIPE. 


ANTIMONY  AND  ITS  COMPOUNDS.— Continued. 

f     Ker-  SbaOSa.  Oxysulphide  resulting  from  decomposition  of  stibnite,  etc. 

mesite — 
•{       cherry-       Antimony, 

red  vari-  75*. 

I       ety. 

Apatite        3CasP2O8        Reacts  for   phosphorus.     (See   phosphate    rock.)      Distinguished 
(Phos-          +  CaFa.  from  beryl  by  its  inferior  hardness,  being  easily  scratched  with 

phorite).  a  knife;  from  calcite  by  no  effervescence  with  acids;  from  pyro- 

Phosphate          n:orphite  (lead   phosphate)  by  its   difficult  fusibility,  and  giving 
of  lime,  B.  B.   no    metallic   reaction.     The  last  affords  B.  B.   a  globule 

92.25^.         which  becomes  angular  or  crystalline  on  cooling.     Brittle,  trans- 
parent to  opaque. 

Occurs  in  rocks  of  various  kinds,  but  more  frequently  in  those  of 
a  metamorphic  crystalline  character,  as  in  Laurentian  gneiss, 
which  is  usually  hornblendic,  granitic,  or  quartzose  in  character, 
in  Canada,  and  in  association  with  granular  limestone.  Also 
found  in  veins  traversing  granite  and  in  many  metalliferous 
veins,  also  disseminated  in  beds  of  iron  ore  and  in  mica  schist, 
and  sometimes  associated  with  tin  in  gneiss,  syenite,  etc.  Fre- 
quently found  associated  with  such  minerals  as  pyroxene,  amphi- 
bole,  titanite,  zircon,  garnet,  etc.,  etc. 


On  charcoal  much  the  same  as  stib- 
nite. 


In  forceps  infusible  except  at  edges, 
coloring  flame  reddish  yellow; 
moistened  with  H2SO4  colors  flame 
feebly  green. 


CHARACTERS. 

COLOR.              LUSTRE. 

STREAK 

BILITY. 

HARD- 
NESS. 

SP.  GR. 

CRYS- 
TALLI- 

MAGNETIC 
BKFORK                                   USES. 

OR  AFTER 

TREATMENT  WITH  ACIDS.ETC. 

ZATION. 

HEATING. 

In    open    tube     reacts 

Cherry-red.      Ada- 

Brown- 

I 

1.1 

4-6 

V. 

See  under  heading  ANTIMONY, 

like  stibnite. 

mantine 

red. 

etc. 

to  me- 

tallic. 

.... 

. 

Slowly  soluble  in  nitric 

Variable,  but     Vitre- 

Whit- 

Quiet- 

5 

3.20 

III. 

The  principal  use  of  apatite 

acid.     Insoluble  in  di- 

generally        ous, 

ish. 

ly  at 

is  as  a  source  of  phosphoric 

lute  HC1.     Acetate  of 

tinged  sea-       never 

5- 

acid   and    phosphorus,    and 

lead    added    to   nitric 

green  or            bright, 

' 

before  the  discovery  of  the 

solution  (not  too  acid) 

grayish             inclin- 

phosphate-rock    deposits  in 

causes   a   heavy    pre- 

green, yel-       ing  to 

Florida  was  largely  sold  to 

cipitate  of  phosphate 

low,  blue,        sub- 

the  manufacturers  of  fertil- 

of   lead.      Molybdate 

brown,  red      resinous 

izers,  its  value  for  them,  as 

of  ammonium  added  to 

and  gray, 

in    the   case    of    phosphate 

solution  gives  a  bright 

sometimes 

rock,    depending    upon    the 

yellow  precipitate.    In 

colorless. 

percentage  of  phosphate  of 

a  closed  tube  it  affords 

lime  which  it  contains.   (See 

no  water. 

phosphate  rock.) 

- 

2 

i 

NAME. 


COMP.  AND 
PKRCBNTAGE 
OF  IMPORTANT 
CONSTITUENT. 


GENERAL  CHARACTERS  AND  ASSOCIATIONS. 


SPECIFIC 


BEFORE  BLOWPIPE. 


ARSENIC  AND  ITS  COMPOUNDS. 

Heated  on  charcoal  volatilizes  with  white  incrustation,  which  is  deposited  far  from  assay,  and  which  is  easily  driven  off  oy 
assay,  with  alliaceous  fumes.  When  flame  is  applied  to  this  sublimate  it  volatilizes,  and  the  characteristic  brilliant  but  minute 
small  quantities  are  mixed  with  lead  it  is  used  in  the  manufacture  of  small  shot.  When  added  to  iron  and  steel  it  is  used  for  the  munu- 
useful  articles  being  made  from  the  alloy.  Also  used  to  a  certain  extent  in  agriculture,  in  the  manufacture  of  certain  kinds  of  glass,  and 

NOTE. — Considerable  quantities  are  now  obtained  from  the  reduction  of  cobalt  and  nickel  ores  as  a  by-product. 


Native.        As. 


Very  brittle  and    friable.     Easily  pulverized. !   Soon    oxidizes   on 

exposure,  producing  black  crust. 
Occurs   principally  in   veins  in  crystalline  rocks  associated   with 

ores  of  antimony,  lead,  silver,  etc. 


Arseno- 
pyrite 
(Mis- 
pickel). 


Orpi- 

ment. 


FeAsS. 

Arsenic, 

46.0*. 


AsjSi. 
Arsenic, 


Common  ore.     Brittle.     When  associated  with  nickel  and  cobalt 

ores  it  reacts  for  these  two  metals. 
Found  principally  in  crystalline  rocks,  associated  with  ores  of  lead, 

silver,  tin,  also  with  pyrite,  chalcopyrite,  and  sphalerite. 


Small   crystals   with    smooth    surface,   and    irregularly   clustered 

together  or  in  foliated  or  fibrous  masses. 
Found  associated  with  realgar,  native  arsenic,  and  calcite. 


. 


Volatilizes  at  356°  without  under- 
going fusion,  and  burns  with  pale- 
bluish  flame  when  heated  just 
below  redness.  Gives  a  white 
coating  on  coal,  and  affords  a  garlic 
odor. 

Gives  fumes  of  arsenic;  in  R.  F.  be- 
comes black  and  attractable  by  th£ 
magnet,  owing  to  presence  of  iron. 
In  closed  tube  first  red  sublimate, 
then  lustrous  black  sublimate  of 
metallic  arsenic;  in  open  tube  sul- 
phurous fumes  and  white  sublimate 
of  arsenic  trioxide. 

Reacts  for  arsenic  and  sulphur.  Fuses 
readily  and  volatilizes,  and  with 
soda  on  charcoal  gives  arsenical 
fumes  and  a  blue  flame. 


28 


CHARACTERS. 

TREATMENT  WITH  ACIDS, ETC. 


COLOR. 


LUSTRE.       STREAK 


Fust- 

BIL1TY. 


HARD- 
NESS. 


SP.  GR. 


MAGNETIC 


OR  AFTER 

HEATING. 


In  closed  tube  gives  brilliant  black  sublimate  near 
USES. —  Used  in  dyeing  and  calico-printing.      When 


the  flame.     When  abundant  easily  recognized  by  garlic  odor  of  the  fumes. 

octahedral  crystals  of  oxide  of    arsenic  are  deposited  further  up  the  tube. — 

facture  of  chains  and  ornaments,  the  combination  affording  a  brilliant  polish.     It  is  also  alloyed  with  copper,  many  ornamental  and 

in  medicine.      The  ores  were  used  to  a  greater  extent  formerly  than  now  in  the  production  of  certain  colors. 


Gives   in    closed    tube 
metallic  arsenic. 


Reacts  for  arsenic,  sul- 
phur and  iron.  Soluble 
in  nitric  acid,  with  sep- 
aration of  sulphur. 
In  solution  ammonia 
gives  reddish  -  brown 
precipitate  (ferric  hy- 
drate). 


1 O 

and    caustic     potash. 

HC1  precipitates  from 

this     latter     solution 

lemon-yellow  flocks. 


Tin-white,         Metal-        Tin-        Vol.            3.5           5.7           III.                           See  under  heading  ARSENIC, 

light  to               lie.             white,      with-                                                                            etc. 

lead-gray,                           etc.,    ,     out 

tarnishes                             like           fu- 

grayish                                color.        sion. 

black. 

. 

.  -"I 

• 

Silver-white     Metal-        Gray-          2            5.5           6.2          IV.        After.         See  under  heading  ARSENIC, 

to  steel-            lie.             black.                                                                                       etc. 

gray. 

Fine  golden 
or  lemon- 
yellow. 

Pearly,       Paler      Easily 
resin-          yel- 
ous.             low 
than 
color. 

1-5 

3-5 

IV. 

See  under  heading  ARSENIC, 
etc. 

NAME. 


COMP.  AND 
PERCENTAGE 
OF  I  IMPORTANT 
CONSTITUENT. 


GENERAL  CHARACTERS  AND  ASSOCIATIONS. 


SPECIFIC 


BEFORE  BLOWPIPB. 


ABSENIC  AND  ITS  COMPOUNDS.— Continued. 

Realgar.      AsS.                 Easily  recognized  by  its  color,  etc.     Sectile,  granular,  compact  or  On  charcoal  same  as  above.    In  closed 

incrustating.  tube  melts,  volatilizes,  and  makes  a 

Arsenic,          Often  associated  with  orpiment  and  ores  of  silver,  etc.  transparent  red  sublimate.     In  open 

7O.i£.  tube  when  heated  carefully  yields 


Asbestos 
(Moun- 
tain 
Cork; 
Moun- 
tain 

Leather). 


(CaMgFe) 
SiOs. 

Variable. 


Several  varieties.  Finely  fibrous  (amianthus)  and  fibres  easily 
separable.  Variety  of  hornblende  (actinolite)  or,  commercially 
speaking,  of  serpentine. 

Chrysotile  (commercial  asbestos)  is  largely  mined  in  the  serpentine 
belt  of  Canada,  Province  of  Quebec,  where  it  is  usually  found 
filling  small  cracks  or  seams  in  the  fractured  serpentine.  True 
asbestus,  mineralogically  considered,  is  oi  but  small  economic 
importance. 


white     sublimate     of 
oxide. 


arsenic    tn- 


Gives    same  reaction  as  hornblende, 
which  see. 


CHARACTERS. 

TREATMENT  WITH  ACIDS,  ETC. 


COLOR. 


LUSTRE.   STREAK 


FUSI- 
BILITY. 


HARD- 
NESS. 


SP.  GR. 


CRYS- 

TALLI- 


MAGNETIC 
BEFORE 


USES. 


Dissolves  with  difficul- 
ty in  aqua  regia,  sul- 
phur being  precipitat- 
ed. Boiled  with  caustic 
potash  is  decomposed, 
leaving  a  brown  pow- 
der undissolved. 

The  pure  variety  is 
distinguished  from 
some  varieties  of  fi- 
b  r  o  u  s  serpentine 
which  much  resemble 
it  (e.g..  chrysotile, com- 
mercially sometimes 
known  as  bostonite}  by 
yielding  no  water  in 
closed  tube  and  not 
being  readily  acted 
upon  by  acids. 

Chrysotile,  or  the  as- 
bestos of  commerce, 
affords  much,  water  in 
closed  tube. 


Light  or  au- 

Resin- 

Au- 

Easily     1.5-2         3.5           V. 

rora-red, 

ous, 

rora- 

scarlet-red 

trans- 

red to 

to  orange- 

lucent 

orange- 

yellow. 

to 

red. 

trans- 

parent. 

White, 

Fibrous, 

White, 

6.                 5-5           3-2 

V. 

greenish 
white. 

silky  or 
satin- 

slight- 
ly. 

Around          or              or. 
edges        2<5_4      2.5-2.6 

green,  yel- 
low, brown- 

like. 

shin- 
ing. 

with 
diffi- 

ish. 

culty. 

31 


Besides  being  an  ore  of  ar- 
senic, it  is  somewhat  used 
in  the  manufacture  of  fire- 
works, especially  for  the 
production  of  what  is  known 
as  White  Indian  Fire. 


It  is  largely  used  for  fire-proof 
clothing  (for  which  the  fibres 
must  be  long),  for  the  pack- 
ing of  pistons  and  valves,  for 
the  covering  of  steam  pipes 
and  boilers,  and  in  many  oth- 
er caseswhere  such  fire-proof 
and  non-conducting  material 
as  asbestos-cloth  may  be  de- 
sirable. It  is  also  used  in 
making  liquid  and  fire-proof 
paints,  fire-proof  cements, 
sheet  and  roll  millboard  and 
flooring,  and  in  combination 
with  hair-felts  and  other  sub- 
stances. 


NAME. 


Barite 
(Heavy- 
spar; 
a  Vein- 
stone). 


COM  p.  AND 
PERCENTAGE 
OF  IMPORTANT 
CONSTITUENT. 

BaSO4. 


GENERAL  CHARACTERS  AND  ASSOCIATIONS. 


Usually  recognizable  by  its  weight,  and  the  fact  that  it  decrepitates 
and  colors  the  flame  yellowish  green  when  ignited  in  forceps. 
(See  Flame  Colors  in  Appendix.) 

Often  found  in  connection  with  and  as  the  gangue  of  many  of  the 
metallic  ores,  such  as  cobalt,  lead,  manganese,  etc.;  also  with 
silver,  copper,  etc.  Occurs  throughout  the  Rocky  Mountain 
region  and  Missouri  and  elsewhere — in  New  Jersey,  North  Caro- 
lina, Virginia,  etc.  It  is  rarely  found  in  connection  with  gold 
ore,  e.g.,  Huanaco,  Chile. 


SPECIFIC 


BEFORE  BLOWPIPE. 


Distinguished  from  lead  carbonate  by 
the  foregoing,  and  the  fact  that  it 
yields  on  charcoal  no  metallic  glob- 
ule, and  does  not  react  for  lead.  On 
charcoal  reduced  toa  sulphide.  With 
soda  gives  at  first  a  clear  pearl,  but 
on  continued  blowing  yields  a  he- 
patic mass,  which  spreads  out  and 
soaks  into  the  coal.  If  a  portion  of 
this  mass  be  removed,  placed  on  a 
clean  silver  surface,  and  moistened, 
it  gives  a  black  spot  of  silver  sul- 
phide. Should  the  barite  contain 
calcium  sulphate,  this  will  not  be 
absorbed  by  the  coal  when  treated 
in  powder  with  soda.  (Dana.) 


BISMUTH  AND  ITS  COMPOUNDS. 

Its  presence  is  detected  by  characteristic  lemon  or  orange  sublimate,  which  it  and  its  compounds  give  when  treated  alone  or 
Readily  dissolved  by  nitric  acid,  which  solution,  when  concentrated,  gives  white  precipitate  when  poured  into  excess  of  water.  The 
metals,  e.g.,  in  the  manufacture  of  pewter ers"  solder,  mosaic  gold,  etc.;  also  used  in  the  manufacture  of  type-metal  and  fusible  metal.  The 
colors,  while  the  basic  nitrate  is  used  as  a  cosmetic  and  in  medicine.  The  ores  follow. 


CHARACTERS. 

TREATMENT  WITH  ACIDS,ETC. 


O,OR.  LUSTRE. 

1  -  ^  -  1 


STREAK 


HA». 


s,  G, 


CRYS         MAGNETIC 
;        ^^ 

HEATING. 


UsK, 


With    soda    gives    sul-     Generally          Vitre-         Whit- 
phur  reaction.     Insol-      whitish,  but      otis  to          ish. 
uble  in  acids.                      of  all  colors       resin- 

3 

3 

4-5 

IV. 

Used  chiefly  in  the  manufac- 
ture of  pigments,  as  a  cheap- 
er substitute  for  white  lead, 

—  yellow,           ous; 
brown,  blue,      some- 

or  in  the  adulteration  of  the 
latter.  It  is  also  used  to  a 

. 

etc. 

times 
pearly 
trans- 
lucent. 

much    smaller    extent   as   a 
makeweight  by  paper  manu- 
facturers, and  in  the  prepara- 
tion of  canvas  covers,  etc. 

xJj^f^A^Sv 

ff       ^   OF  THE 

f  UNIVERSITY  1 

^—  -~" 

with  soda  on  charcoal  before  blowpipe  in  R.  F.     With  sulphur  and  potassium  iodide  gives  a  scarlet  coating  far  from  the  assay. 

ores  are  rare,  the  supply  being  furnished  principally  by  the    native  metal. USES. — Principally  used  as  an  alloy  -with  other 

salts  are  quite  extensively  employed  for  various  purposes,  the  oxide  with  boric  and  silicic  acids  being  used  for  optical  glasses,  for  porcelain 


NAME. 


COMP.  AND 
PERCENTAGE 
OF  IMPORTANT 
CONSTITUENT. 


GENERAL  CHARACTERS  AND  ASSOCIATIONS. 


BISMUTH  AND  ITS  COMPOUNDS.— Continued. 


Native.        Bi. 


Bismuth 
Glance 
(Bis- 
inuthin- 
ite  or 
Sulphide 
of  Bis- 
muth). 


BiaS,. 

Bismuth, 
81.2*. 


Brittle  and  somewhat  malleable.  Occurs  in  arborescent  shapes; 
foliated  and  granular.  Found  usually  in  connection  with  ores 
of  cobalt,  nickel,  silver,  lead,  and  zinc,  and  sometimes  iron;  also 
in  quartz  with  wolframite,  scheelite,  blende,  and  galena. 


Opaque,  soft,  and  brittle.  Fuses  in  flame  of  candle.  Found  in 
connection  with  tin,  gold,  and  other  metallic  ores,  such  as  pyrite, 
chalcopyrite,  magnetite,  limonite,  etc.;  also  with  garnet,  barite, 
apatite,  etc. 


SPECIFIC 


BEFORE  BLOWPIPE. 


Fuses  easily,  with  odorless  fumes, and 
does  not  continue  to  burn  after  re- 
moval from  the  flame.  The  globule 
is  brittle  when  cold,  but  somewhat 
malleable  when  heated.  Volatilizes 
after  long  blowing, and  imparts  to  the 
coal  at  first  a  white  coating,  which 
becomes  partly  yellow  and  partly 
orange.  The  color  slightly  fades  on 
cooling  and  becomes  lemon-yellow. 
In  glass  tube  it  yields  scarcely  any 
fumes,  and  the  metal  becomes  sur- 
rounded with  fused  oxide  of  a  dark- 
brown  color,  which  changes  to  yellow 
on  cooling.  By  this  deportment  it 
can  be  easily  distinguished  from  na- 
tive antimony  and  tellurium. 

Fuses  in  R.  F.,  with  effervescence, 
giving  a  globule  of  bismuth  and 
characteristic  coating.  In  open 
tube  sulphurous  fumes  and  white 
sublimate  which  B.  B.  fuse  into 
drops,  brown  when  hot  and  yellow 
on  cooling. 


34 


CHARACTERS. 


TREATMENT  WITH  ACIDS,ETC. 


COLOR. 


LUSTRE.       STREAK 


FUSI- 
BILITY. 


HARD- 
NESS. 


*>••**  ft  X  •  ltE.00. 

J 1 


SP.  GR. 


CRYS- 
TALLI- 
ZATION. 


MAGNETIC 
BEFORE 

OR  AFTER 
H  EATING. 


USES 


In  nitric  acid  soluble 
without  difficulty.  The 
concentrated  solution 


Reddish  sil- 
ver-white. 
Subject  to 


Metal- 
lic. 


White 
like 
color. 


2.5 


9-7 


III. 


See  under  heading  BISMUTH, 
etc. 


yields  a  white  precipi- 
tate   on    addition    of 

tarnish. 

much  water. 

'' 

1 

.: 

1 

Soluble  in   nitric  acid. 
Water    added    causes 

Tin-white  to     Metal-        Gray,          I              2            6.5          IV. 
lead-gray,         lie.              some- 

See  under  heading  BISMUTH, 
etc. 

solution     to     become 

sometimes                           times 

' 

turbid,      and      finally 
yields  a  white  precipi- 
tate of   bismuth  oxy- 

yellowish                             with 
white.                                   irides- 
cent 

nitrate. 

tar- 

nish. 

1  • 

~~J 

5 

NAME. 


COMP.  AND 

PERCENTAGE 
OF  IMPORTANT 
CONSTITUENT. 


GENERAL  CHARACTERS  AND  ASSOCIATIONS. 


CALCIUM  AND  ITS  COMPOUNDS. 

The   presence  of   calcium  may  be  often  detected  by  the   fine  orange-red  color  which   its  compounds   impart  to  blowpipe 
precipitate  (CaCO3)  which  is  soluble  in  acids,  with  effervescence  (COa). 


SPECIFIC 


BEFORE   BLOWPIPE. 


Calcite. 

CaCO3. 

(Calc 
Spar) 
(a  Vein- 

Calcium 
carbonate 

stone, 

=  loo  or 

etc.). 

Many 

Lime  = 
56*,  etc. 

varie- 

ties. 

Lime- 
stones 
(mas- 
sive). 


Generally 
more  or 
less  im- 
pure. 


Usually  shows  distinct  rhombohedral  cleavage.  Easily  scratched 
with  knife.  When  deposited  from  calcareous  springs  (usually 
hot)  or  streams,  or  in  caverns,  called  variously  calcareous  sinter, 
travertine,  stalactites,  stalagmites,  Mexican  onyx,  etc.,  in  which 
the  peculiar  and  often  beautiful  banded  appearance  is  due  to  the 
edges  of  the  layers  of  deposition. 

Found  in  seams  and  veins  in  the  many  kinds  of  rock  containing 
lime,  and  especially  in  or  in  close  proximity  to  limestone  strata. 
It  is  usually  a  secondary  deposit  derived  from  the  dissolving  out 
of  the  lime  from  the  rocks  in  or  near  which  it  is  found,  often  in 
veins  in  connection  with  and  as  the  gangue  of  many  of  the 
metallic  ores.  Very  common. 


Infusible.  Held  in  forceps  and  moist- 
ened with  HC1  gives  yellowish-red 
or  orange  color  to  flame. 


All  common  limestones  and  marbles  are  essentially  only  massive  calcite  or  dolomite,  usually  more  or  less 
(See  also  Flame  Colors  in  Appendix.) 


CHARACTERS. 

TREATMENT  WITH  ACIDS,  ETC. 


COLOR. 

LUSTRE. 

STREAK 

FUSI- 
BILITY. 

HARD- 
NESS. 

CRYS- 

SP.  GR.          TALLI- 
ZATION. 

MAGNETIC 

BEFORE 
OR  AFTER 

HEATING. 

USES. 

flame.    Best,  however,  to  test  for  it  in  the  liquid  way.    Carbonate  of  ammonium  produces  in  neutral  calcium   solutions  a  white 


Soluble   in   cold   dilute 
HC1,     with     efferves- 


Colorless, 
white,  and 


Vitre- 
ous to 


White 
or 


Infus 


2.7 


III. 


cence.     i  ne  anute  so- 
lution  gives    no   pre- 
cipitate with  sulphuric 
acid,    but   the    strong 
solution  does. 

01  an  lino.        canny. 
Trans- 
parent 
to 
opaque. 

glilV- 

ish. 

• 

,. 

impure  from  presence  o 

f  clay  or  sands.     For  th 

e  differe 

nt  variet 

ies  see 

pp.  266-! 

568,  Dan 

a's  Min. 

One  of  the  principal  uses  of  calcite 
and  of  the  purer  grades  of  lime- 
stone is  as  a  flux  in  blast-furnaces 
and  for  metallurgical  operations. 
Compact  limestone  is  very  large- 
ly used  as  a  building-stone,  and 
marble  (crystalline  limestone)  is 
largely  employed  for  the  same 
purposes,  as  well  as  for  monu- 
mental, sculptural,  and  ornamen- 
tal purposes.  The  clayey  as  well 
as  the  pure  varieties  are  largely 
used  in  the  manufacture  of  ce- 
ments. It  is  also  used  in  making 
glass  if  not  containing  too  much 
iron  or  other  metallic  oxides  which 
color  the  glass.  Limestone  is  the 
best  and  cheapest  stone  for  rail- 
way ballast  and  'macadamizing.  Used  extensively 
for  curbstones,  in  bridge-building,  etc.,  etc.  Large 
quantities  (usually  scrap-marble)  are  used  in  the 
manufacture  of  carbonic  acid  gas  for  the  many 
purposes  for  which  this  gas  is  employed,  and 
when  calcined  it  is  largely  used  in  making  mor- 
tar, chloride  of  lime,  and  as  a  fertilizer.  Very 
fine-grained  and  compact  limestone  is  employed 
as  a  lithographic  stone,  but  beds  of  limestone 
affording  good  lithographic  stones  are  very  rare. 
The  uses  of  limestone  are  much  more  varied 
than  those  of  any  other  rock. 


NAME. 


CoMP.  ArfD 

PERCENTAGE 
OF  IMPORTANT 
CONSTITUENT. 


GENERAL  CHARACTERS  AND  ASSOCIATIONS. 


CALCIUM  AND  ITS  COMPOUNDS.— Continued. 

Dolomite     (CaMg)  Common  magnesian  limestone.     Generally  very  impure.     Distin- 

(mas-                      CO8.  guished  from  common  limestone  by  no  effervescence  with  dilute 

sive).  cold    HC1,  or  only  very  feeble.     Much    "hydraulic"  limestone 

Calcium  (so  called  from  the  fact  that  it  sets  after  ignition  and  becomes 

carbonate  solid  under  water),  used  in  making  cements,  is  here  included. 

=  54.35.  Frequently  associated  with  serpentine  and  other  magnesian  rocks, 

Magnesium  and  with  ordinary  limestones.     Often  forms  massive  and  exten- 

carbonate  sive  strata.     Sometimes  associated  with  gypsum,  rock-salt,  and 

=  45.65,  other  results  of  the  evaporation  of  saturated  saline  waters, 
etc. 


SPECIFIC 


BEFORE  BLOWPIPE. 


Harder  than  calcite,  but  sometimes 
chemical  analysis  required  to  dis- 
tinguish between  the  two.  After 
ignition  reaction  alkaline. 


Gypsum       CaSO4  Scratched  by  the  nail.      Hydrous  calcium  sulphate.     This  when 

(mas-  +  2HaO.         compact  is  so-called  alabaster,  or  when  burned  plaster  of  Paris, 

sive).  Frequently  associated  with  beds  of   rock  salt,  caliche  (Chile  salt- 

peter), etc.  Also  associated  with  pyrite,  sulphur,  etc.  It  is 
often  produced  where  the  decomposition  of  pyrites  has  an 
opportunity  to  affect  adjacent  limestone.  Also  associated  with 
dolomite  and  anhydrite. 


40 


Becomes  instantly  white  and  opaque, 
and  exfoliates,  then  fuses  to  a  glob- 
ule, having  an  alkaline  reaction. 
When  ignited  at  a  temperature  not 
exceeding  260°  it  again  combines 
with  water  and  becomes  firmly 
solid.  Gives  sulphur  reaction  with 
soda  in  R.  F. 


CHARACTERS. 


TREATMENT  WITH  ACIDS,  ETC. 


COLOR. 


LUSTRE.       STREAK 


FUSI- 
BILITY. 


HARD- 
NESS. 


SP.  GR. 


CRYS- 
TALLI- 
ZATION. 


MAGNETIC 

BEFORH 
OR  AFTER 

HEATING. 


USES. 


Effervesces  in  hot  but     White,  gray,     Vitre-         Whit-      Infus.      3.5-4         2.8           III. 

Many  of  the  massive  kinds  af- 

not in  cold  hydrochlo-      brown,  etc.       ous  to         ish. 

ford  good  hydraulic  lime,  and 

ric  acid.  Concentrated                                   pearly 

when  of  the  proper  color  are 

solution     gives      with 

to  dull. 

sometimes  used  as  marble  for 

sulphuric   acid  a  pre- 

architectural and  ornamental 

cipitate  of  sulphate  of 

purposes.     It  is  largely  used 

lime. 

as  a  building-stone.     Often 

used  for  the  bricks  employed 

in  the  manufacture  of  steel 

by   what   is    known    as   the 

"  Basic  "  process.   (See  mag- 

nesium, etc.) 

In   closed    tube    gives     Colorless   to     Pearly,       White        2.5             2             2.3 

V. 

One  of  the  principal  uses  is  in 

much    water    and   be-      gray    dirty-      silky, 

making  plaster  of  Paris  and 

comes   opaque.      Dis-      white,  and        vitre- 

for  the  manufacture  of  arti- 

solves  quietly  in  much      various              ous. 

ficial  marble.     It  is  also  used 

HC1,  and  the  solution      shades.              Some- 

as  a  fertilizer  or  land-plaster. 

gives  a  heavy  precipi-                                   times 

and  when  pure  in  its  natural 

tate  with  barium  chlo- 

dull, 

state  it  is  carved  into  orna- 

ride.  Soluble  in  400  to 

earthy. 

mental  objects.  It  is  used  also 

500  parts  of  water. 

' 

in  making  certain  cements. 

4 

L 

NAME. 


COMP.  AND 

PERCENTAGE 
OF  IMPORTANT 
CONSTITUENT. 


GENERAL  CHARACTERS  AND  ASSOCIATIONS. 


CALCIUM  AND  ITS  COMPOUNDS.— Continued. 


Anhydrite 
(Variety 
"Flos- 
Ferri"  or 
"  Flower 
of  Iron") 


CaSO4.  It  is  an  anhydrous  calcium   sulphate;  fibrous  and  lamellar;  often 

contorted;  coarse  and  fine  granular  and  compact.  (Compare 
gypsum.)  Found  very  often  with  rock-salt  and  gypsum,  into 
which  it  often  passes  by  absorption  of  moisture.  Sometimes 
forms  extensive  beds. 


SPECIFIC 


BEFORE  BLOWPIPE. 


Reactions  same  as  those  of  gypsum. 
Cleaves  easily  in  three  directions 
into  square  blocks. 


Aragon-       CaCO,. 
ite. 


Much  resembles  calcite,  but  is  not  cleavable  parallel  to  rhombo- 
hedron;  also  distinguished  from  it  by  its  higher  specific  gravity 
and  crystalline  form.  Transparent  to  translucent. 

Often  found  in  connection  with  iron  ores  and  in  basalt  and  trap- 
rocks.  Sometimes  associated  with  copper  and  iron  pyrites, 
galena,  malachite,  etc. 


Falls  to  powder,  in  which  it  differs 
from  calcite.  When  containing 
strontium  imparts  more  of  a  scarlet 
color  to  flame. 


Celestite.     SrSO«.  Differs  from  baryta  in  the  bright-red  color  of  flame  (strontium). 

(See  Flame  Colors  in  Appendix.) 

Strontium,      Usually  found  in  the  older   formations,  in   sandstones  and  espe- 
47.6j(.         cially   in   limestones.     It   is  commonly  associated  with  gypsum, 
rock-salt,  and  sulphur.    Occasionally  in  connection  with  some  of 
the  metallic  ores  such  as  galena  and  sphalerite. 


With  soda  in  R.  F.  gives  a  sulphur 
reaction.  Frequently  decrepitates 
coloring  flame  red. 


CHARACTERS. 


TREATMENT  WITH  ACIDS.ETC. 


COLOR. 


LUSTRE.        STREAK 


FUSI- 
BILITY. 


HARD- 
NESS. 


SP.  GR. 


CRYS- 
TALLI- 
ZATION. 


MAGNETIC 
BEFORE 

OR  AFTER 

HEATING. 


USES. 


Same  as  with  gypsum, 
except  in  closed  tube  it 
gives  no  water.  Is  not 
precipitated  by  bi- 
chloride of  platinum; 
insoluble  in  water. 


Behavior  with  acids 
same  as  for  calcite, 
which  it  much  resem- 
bles, but  from  which  it 
is  further  distinguish- 
ed by  different  crystal- 
line form,  absence  of 
rhombohedral  cleav- 
age, and  higher  spe- 
cific gravity. 


White,  or 
tinged  with 
gray,  red,  or 
blue. 

More  or 
less 
pearly, 
or  vit- 

Gray-       2-3 
ish 
white. 

reous, 

trans- 

parent 
to  sub- 

trans- 

lucent. 

3-3-5        2.95 


IV. 


Colorless; 

Vitre- 

Un- 

white,  with 

ous  to 

cblored 

light  tinges 

resin- 

of gray,  yel- 

ous on 

low,   green, 

broken 

and  violet. 

sur- 

face. 

Infus.      3.5-4       2.9-3 


IV. 


A  scaly  variety  containing  a 
small  amount  of  silica,  and 
known  as  vulpinite,  is  some- 
times cut  and  polished  for 
ornamental  purposes. 


May  possibly  be  used  for 
some  of  the  same  purposes 
as  calcite,  but  of  small  im- 
portance in  the  arts. 


Very  little  acted  on  by 
HC1,  or  HNO,. 

Colorless,          Vitreous,      White 
white,    blu-      pearly. 
ish,and>ed-      Trans- 
dish,                  parent 
to  sub- 
trans 
lucent. 

3 

3-3-5 

^- 

3-9 

IV. 

Its  principal  use  is  for  mak- 
ing nitrate  of  strontia  which 
Is  largely  employed  in  pro- 
ducing a  red   color  in  fire- 
works. 

4 

1 

NAME. 


COMP.  AND 
PERCENTAGE 
OF  IMPORTANT 
CONSTITUENT. 


GENERAL  CHARACTERS  AND  ASSOCIATIONS. 


SPECIFIC 


BEFORE  BLOWPIPE. 


CHLORINE. 

This  element,  though  not  occurring  in  a  free  state  in  nature,  is  largely  used  and  frequently  met  with  through  the  many 
Chlorides  when  heated  with  strong  sulphuric  acid,  save  those  of  mercury,  silver,  and  tin,  evolve  hydrochloric  acid  gas, 
off,  recognizable  by  its  irritant  odor,  green  color,  power  of  bleaching  litmus,  etc.,  and  by  the  purple  stain  it  produces  on  a  piece  of 
furnish  a  mass  which  when  warmed  with  strong  sulphuric  acid  gives  off  deep-red  vapors  of  chromic  chloride,  CrOCla,  decomposable 
rendered  ammoniacal.  (Odling.)  Fused  in  a  bead  of  microcosmic  salt  saturated  with  CuO  imparts  an  azure-blue  color  to 
chemistry,  in  the  manufacture  of  chloride  of  lime,  chloride  of  potassium,  etc.  Chloride  of  lime  is  largely  used  as  a  disinfectant  and 
liberated.  Chlorine  is  one  of  the  best  disinfectants  or  deodorizers  known,  or  furnishes  the  basis  for  them.  It  is  also  quite  largely  used  in 

CHROMIUM:  AND  ITS  COMPOUNDS. 

Exists  chiefly  in  two  native  compounds,  viz.,  crocoite  (Siberia)  or  chromate  of  lead,  and  chromite  or  oxide  of  chromium  and 
slightly  magnetic.  Fuses  slightly,  is  soluble,  and  imparts  a  beautiful  emerald-green  color  to  beads  of  borax  and  salt  of  phos- 
(the  chrome-yellow  of  commerce).  Bichromate  of  potash  (which  is  the  salt  from  which  all  the  others  are  obtained)  is  quite  extensively 
of  very  hard  grades  of  steel  known  as  chrome  steel. 


" 


Chromite     FeCrjCs.  In  many  varieties  quite  strongly  magnetic;  in  others,  only   very 
(Chromic  feebly.     Usually  found  associated  with  serpentine  (altered  peri- 

Iron).  Chromium          dotite)  in  which  it  forms  irregular  embedded  masses  or  veins. 

Sesqui-  Sometimes   found   associated  with   gold,  pyrite,    galena,    quartz, 
oxide,  68*.         etc.     Commercially  speaking,  the  only  ore. 


In  O.  F.  infusible.  In  R.  F.  becomes 
slightly  rounded  on  edges  and  be- 
comes more  magnetic.  Best  test  is 
that  it  imparts  a  beautiful  charac- 
teristic emerald-green  color  to  beads 
of  borax  and  salt  of  phosphorus 
when  cold.  This  color  is  heightened 
by  fusion  on  charcoal  with  metallic 
tin. 


CHARACTERS. 

TREATMENT  WITH  ACIDS,  ETC. 


COLOR. 

LUSTRE. 

STREAK 

FUSI- 
BILITY. 

HARD- 
NESS. 

CRYS- 
SP.  GR.        TALLI- 

ZATION. 

MAGNETIC 

BEFORE                                                     »T 
OR  AFTER                                                  USES* 

HEATING. 

compounds  which  it  forms,  such  as  chloride  of  ammonium,  copper,  mercury,  potassium,  sodium,  tin,  silver,  etc.,  which  see. 
known  by  its  pungent  smell  and  acid  reaction.     When  heated  with  peroxide  of  manganese  and  sulphuric  acid,  chlorine  gas  is  given 
starch-paper  moistened  with  iodide  of  potassium.    When  fused  with  a  little  carbonate  of  sodium  and  red  chromate  of  potassium,  they 

flame. USES.— Common  salt  (chloride  of  sodium}  is  the  form  in  which  chlorine  is  most  frequently  met  with.     It  is,  however,  used  in 

deodorizer.     Much  the  same  results  have  been  lately  obtained  by  passing  a  current  of  electricity  through  sea-water,  free  chlorine  being  thus 
the  recovery  of  gold  from  its  ores  by  what  is  known  as  the  "  chlorination  "  process. 


iron.     It  is,  when   reduced  to  metallic  state,  a  whitish,  brittle,  and   very   infusible  metal.      Chief   source  is  chromite,  which  is 
phorus  when  cold. USES. — Its  compounds  are  used  in  imparting  a  green  color  to  glass  and  in  the  production  of  chromate  of  lead 


employed  in  calico-printing.     It  also  has 

various  other  uses. 

An  increasing  quantity  of  chrome 

-iron  ore  is  being  used  in  the  manufacturt 

—-                                            1              .                                  1 
Only  slightly  attacked     Iron-black,       Sub-            Yel- 
by   HC1,    but    soluble      pitch-black       metallic     low- 
by   fusion     in     bisul-      to  brown-         to  me-       ish 
phate    of     potash    or      black.                tallic.         brown 
soda.                                                                                   to 
dark 

__, 
Infus. 

5-5 

4-3 

I. 

Both.          See  under  heading   CHROMI 
Some-            UM,  etc. 
times 
but 
slightly. 

brown 

• 

f 

41 

> 

GENERAL  CHARACTERS  AND  ASSOCIATIONS. 


SPECIFIC 


BEFORE  BLOWPIPE. 


CHROMIUM  AND  ITS  COMPOUNDS.— Continued. 


Chro- 
mate  of 
Lead 
(Croco- 
ite). 
Very 


PbO4Cr.          This   is  chiefly  manufactured   from   above,  and  is   known  as  the     Blackens  and  fuses  and  forms  a  shin- 


Chromium 
trioxide, 
31- 1*- 


"  chrome-yellow"  of  the  painter.  Occurs  very  rarely  in  nature 
in  metamorphic  rocks  (gneiss  or  granite),  associated  with  gold, 
pyrites,  galena,  quartz,  etc.  ...... 


ing  slag  containing  globules  of  lead. 
Gives  emerald-green  bead  in  both 
flames. 


COALS. 

These  may  be  generally  easily  recognized  by  their  physical  characters,  which  are  too  well  known  to  require  description.  "  It 
bituminous  matter  to  anthracite,  and  further  to  kinds  which  approach  graphite."  Each  species  gives  variable  analyses  according 

NOTE. — A  coking  coal  rs  a  bituminous  coal  which  softens  or  becomes  pasty  or  semi-viscid  in  the  fire.  This  is  attended  with 
or  less  coherent  grayish-black  cellular  or  fritted  mass  is  left,  which  is  coke,  or  the  part  not  volatile,  and  which  varies  from  50-85^. 
in  general  composition,  but  it  burns  freely  without  softening  or  any  appearance  of  incipient  fusion.  The  "  coke"  resulting  from 


Anthra-       C  (80-95  Does  not  take  fire  in  lamp-flame.     Hard  as  compared  with  other 

cite.  p.  c.).  varieties  of  coal,  lustrous,  and  breaks  with  conchoidal  fracture. 

Burns  with  a  feeble  flame  of  a  pale  color. 


In  closed  tube  yields  a  little  water 
and  very  little  tarry  product  (bitu- 
men). B.  B.  burns  with  feeble  flame, 
is  slowly  consumed,  and  leaves  but 
little  ash. 


46 


CHARACTERS. 


TREATMENT  WITH  ACIDS,  ETC. 


Reacts     for 
chromium. 


lead    and 


1 

COLOR.               LUSTRK.        STREAK 

FUSI- 
BILITY. 

•  HARD- 
NESS. 

SP.  OR. 

CRYS- 
TALLI- 
ZATION. 

MAGNETIC 

BEFORE 
OR  AFTER 

HEATING. 

USES. 

Bright  red         Trans-        Orange 
or  hyacinth-      lucent        vel" 
red.                     and             low  to 

1-5 

2-5-3 

6 

V. 

: 

.•.-:•' 
-  . 

vitre-         orange 

, 

ous. 

Ada- 

mantine 

1       1   » 

•'•' 

e  original  structure  of  the  wood  (peat,  lignite)  and  through  those  with  less  of  volatile  or 


passes  from  forms  which  still  retain 

to  amount  of  impurities  present. 

escape  of  bubbles  of  gas.     The  volatile  products  resulting  from  the  decomposition  of  the  softened  mass  being  driven 

A  non-coking,  free-burning  coal  may  be  like  the  former  in  all  external  characteristics  and  even  in  percentage  of  volatile 

this  is  not  a  proper  coke,  being  often  in  a  powder  or  in  the  form  of  the  original  coal.     (Dana.) 


off,  a  more 
matter  and 


Boiled   in   solution    of 

Black.                 Brilliant     Black     With        2-2.5          i«5 

Very  extensively   used   as   a 

potassa    it    gives    no 

and  lus-                     some 

fuel  where  great  heat  and  a 

color  to  liquid. 

trous.                         diffi- 

smokeless  fire  are  desirable; 

Subme-                      culty. 

also   usually   admixed   with 

tallic 

coke  for  iron-smelting,  as  in 

iron 

Pennsylvania  and  to  a  less 

black 

extent  in  New  South  Wales. 

' 

and  of- 

• 

ten  iri- 

i 

<• 

. 

descent. 

. 

1                   1 

47 

NAME. 

COALS. 

Semi- 
bitumi- 
nous. 


COMP.  AND 
PBRCKNTAGB 
OF  IMPORTANT 
CONSTITUENT. 


GENERAL  CHARACTERS  AND  ASSOCIATIONS. 


-Continued. 

This  is  the  commercial  name  of  the  variety  which  is  intermediate  between  anthracite  and  the  following,  i.e.,  in  being 
which  yield  upon  analysis,  for  example,  fixed  carbon,  70-85^.     (Pocahontas  Flat-Top  Semi-Bituminous.) 


SPECIFIC 


BEFORE  BLOWPIPE. 


Bitu- 

50-85 p.  c.      Burns  with  bright-yellow  smoky  flame  in  the  fire,  often  with  elimi-     Burns  and  leaves  comparatively  little 

minous 

residue  on         nation  of  bituminous  odor  ;  frequently  breaks  into  cubes.     Upon         ash,  which  varies  with  the  amount 

Coal 

being                  distillation  gives  out  hydrocarbon  oils  or  tar,  hence  name  bitu-         of  silica,  oxide  of  iron,  clay,  etc., 

(coking 

strongly            minous.     Usually  a  firm  compact  texture,  but  fragile  as  compared         present  as  impurities  in  the  coal. 

and  non- 

heated.              with  anthracite. 

coking 

varie- 

ties). 

Lignite 
or  Brown 

Very  vari- 
able. 

Air-dried  lignite  contains  frequently  15-20%  or  more  of  water,  which  it  loses  when  dried  at  no8  C.  or  230°  F. 
Very  abundant;  often  impure;  not  suitable  for  making  commercial  coke,  or  very  rarely,  and  affording 

Coal 

large  proportion  of  volatile  matter.     Variety,  Jet. 

(often 

. 

black). 

Cannel  A  variety  of  bituminous  coal,  which  differs  from  the   purer  varieties  in  often  containing  much  more  extraneous 

Coal.  causes  it  to   be  much    used  in  enriching  gas  coals.     It    is   very  dense  and  compact,    brown  or   black    in    color.     Dull 

splits  and  crackles  or  "chatters"  without  melting;  like  asphaltum.     Burns  readily  with  bright  flame.     Leaves  ash 

a  large   proportion  of  burning  or  lubricating  oils,  much  larger  than  bituminous  coal.     Graduates  into  oil-producing, 

The  variety  Jet  (see  above)  which   is   used  for  ornament   and  jewelry  resembles  cannel  coal,  but  is  harder,  of  a 

land),  in  the  manufacture  of  gas  or  in  enriching other  gas  coals, 

48 


CHARACTERS. 


TREATMENT  WITH  ACIDS,  ETC. 


COLOR. 


LUSTRE.        STREAK 


FUSI- 
BILITY. 


HARD- 
NESS. 


SP.  GR 


CRYS- 
TALLI- 
ZATION. 


MAGNETIC 
BEFORE 

OR  AFTER 


USES. 


less  hard  than  anthracit 

5  and  containi 

ng  more  v 

slatile  m 

atter.     Some  of 

the  Virginia  coa 

s  furnish  good  examples,  such  as  those 

i 

— 

When  heated  in    flask 

Black. 

Black, 

Black. 

Easily      1.5-2        1.14- 

The  most    common    fuel    for 

or  closed   tube   yields 

resin- 

Some- 

1.40 

producing  power  and    heat. 

brown  and   brownish- 

ous. 

times 

The  following  coals  are  em- 

yellow tar  drops  or  oil. 

Some- 

choc- 

ployed forthesamepurposes. 

Imparts  but  little  color 

times 

olate, 

Large    quantities  of  bitumi- 

topotash solutionupon 

pitchy 

col- 

; 

nous  coal  are  converted  into 

boiling.     The  powder 

or 

ored. 

fo&eioruse  in  blast-furnaces, 

boiled  with  ether  im- 

greasy. 

smelting  plants,  and  in  many 

parts      scarcely      any 

other  manufacturing  indus- 

color. 

tries,  as  well  as  for  domestic 

use. 

Gives  a  brown  color  to 

Brown, 

Dull 

Brown, 

Easily      1.5-2        1.13 

liquid  when  boiled  in 

brown- 

and 

black- 

solution of  potassa. 

black  to 

slightly 

ish  to 

black. 

resin- 

black. 

ous. 

earthy  matter,  and  usually  in  containing  much  greater  percentage  of  volatile  bituminous  substances  (hydrocarbons),   which  fact 
earthy  to  brilliant  waxy  lustre.     Not  easily  frangible,   and  breaks  with   uneven   or  largely  conchoidal  fracture.     When  burning  it 
ranging  from  3*  to  2O<*.     Hard  enough  to  take  a  polish.     Affords  on  distillation,  after  drying,  40-66*  of  volatile  matter,  including 
coaly  shales, 
deeper  black  and  higher  lustre,  and  takes  a  more  brilliant  polish. USES. — Used  quite  largely,  as  are  certain  coaly  shales  (Scot- 


NAME. 

COALS. 

Semi- 
bitumi- 
nous. 


COMP.  AND 
PKRCHNTAGK 
OF  IMPORTANT 
CONSTITUENT. 


GENERAL  CHARACTERS  AND  ASSOCIATIONS. 


SPECIFIC 


BEFORE  BLOWPIPE. 


-Continued. 

This  is  the  commercial  name  of  the  variety  which  is  intermediate  between  anthracite  and  the  following,  i.e.,  in  being 
which  yield  upon  analysis,  for  example,  fixed  carbon,  70-85*.     (Pocahontas  Flat-Top  Semi-Bituminous.) 


Bitu- 

50-85 p.  c. 

minous 

residue  on 

Coal 

being 

(coking 

strongly 

and  non- 

heated. 

coking 

varie- 

ties). 

Burns  with  bright-yellow  smoky  flame  in  the  fire,  often  with  elimi- 
nation of  bituminous  odor  ;  frequently  breaks  into  cubes.  Upon 
distillation  gives  out  hydrocarbon  oils  or  tar,  hence  name  bitu- 
minous. Usually  a  firm  compact  texture,  but  fragile  as  compared 
with  anthracite. 


Burns  and  leaves  comparatively  little 
ash,  which  varies  with  the  amount 
of  silica,  oxide  of  iron,  clay,  etc., 
present  as  impurities  in  the  coal. 


Lignite         Very  vari- 
or  Brown      able. 
Coal 

(often 

black). 


Air-dried  lignite  contains  frequently  15-20^  or  more  of  water,  which  it  loses  when  dried  at  no"  C.  or  230°  F. 
Very  abundant;  often  impure;  not  suitable  for  making  commercial  coke,  or  very  rarely,  and  affording 
large  proportion  of  volatile  matter.  Variety,  Jet. 


Cannel  A  variety  of  bituminous  coal,  which  differs  from  the   purer  varieties  in  often  containing  much  more  extraneous 

Coal.  causes  it  to   be  much    used  in  enriching  gas  coals.     It    is   very  dense  and  compact,    brown  or   black    in   color.     Dull 

splits  and  crackles  or  "chatters"  without  melting;  like  asphaltum.     Burns  readily  with  bright  flame.     Leaves  ash 
a  large   proportion  of  burning  or  lubricating  oils,  much  larger  than  bituminous  coal.     Graduates  into  oil-producing, 
The  variety  Jet  (see  above)  which   is   used  for  ornament  and  jewelry  resembles  cannel  coal,  but  is  harder,  of  a 
land),  in  the  manufacture  of  gas  or  in  enrichingother  gas  coals. 


CHARACTERS. 


TREATMENT  WITH  ACIDS,  ETC. 


COLOR. 


LUSTRE.        STREAK 


FUSI- 
BILITY. 


HARD- 
NESS. 


SP.  GR 


CRYS- 
TAL LI. 
ZATION. 


MAGNETIC 
BEFORE 

OR  AFTER 


USES. 


less  hard  than  anthracite  and  containing  more  volatile  matter.     Some  of  the  Virginia  coals  furnish  good  examples,  such  as  those 


t 

Black, 

Black.     Easily      1.5-2        1.14- 

resin- 

Some- 

1.40 

ous. 

times 

Some- 

choc- 

times 

olate, 

pitchy 

col- 

m 

or 

ored. 

greasy. 

Dull 
and 
slightly 

Brown, 
black- 
ish to 

Easily 

1.5-2 

1-13 

resin- 

black. 

ous. 

The  most  common  fuel  for 
producing  power  and  heat. 
The  following  coals  are  em- 
ployed forthesamepurposes. 
Large  quantities  of  bitumi- 
nous coal  are  converted  into 
cokeioTMse.  in  blast-furnaces, 
smelting  plants,  and  in  many 
other  manufacturing  indus- 
tries, as  well  as  for  domestic 
use. 


When  heated  in  flask  Black, 
or  closed  tube  yields 
brown  and  brownish- 
yellow  tar  drops  or  oil. 
Imparts  but  little  color 
topotash  solutionupon 
boiling.  The  powder 
boiled  with  ether  im- 
parts scarcely  any 
color. 


Gives  a  brown  color  to     Brown, 
liquid  when  boiled  in      brown- 
solution  of  potassa.          black  to 
black. 


earthy  matter,  and  usually  in  containing  much  greater  percentage  of  volatile  bituminous  substances  (hydrocarbons),   which  fact 
earthy  to  brilliant  waxy  lustre.     Not  easily  frangible,   and  breaks  with   uneven   or  largely  conchoidal  fracture.     When  burning  it 
ranging  from  3*  to  20%.     Hard  enough  to  take  a  polish.     Affords  on  distillation,  after  drying,  40-66*  of  volatile  matter,  including 
coaly  shales, 
deeper  black  and  higher  lustre,  and  takes  a  more  brilliant  polish. USES. — Used  quite  largely,  as  are  certain  coaly  shales  (Scot- 


NAME. 


COMP.  AND 
PERCENTAGE 
OF  IMPORTANT 

CONSTITUENT. 


GENERAL  CHARACTERS  AND  ASSOCIATIONS. 


SPECIFIC 


BEFORE  BLOWPIPE. 


COBALT  AND  ITS  COMPOUNDS. 

Easily  recognized  by  the  characteristic  deep  sapphire-blue  bead  in  both  flames  with  borax  or  salt  of  phosphorus.  The 
insolubility  of  the  black  sulphides  of  nickel  and  cobalt  in  dilute  HC1  suffices  to  separate  these  metals  from  the  remaining  members 
If  ferrid-cyanide  be  added,  the  precipitate  is  brown-red.  (Do  not  confound  with  similar  precipitate  of  copper.)  Sometimes 

suffices  to  readily  distinguish  the  following  ores  from  arsenopyrite. USES. —  The  principal  use  is  in  the  preparation  of  colors. 

manufacture,  for  enameling  and  tinting  writing-paper,  etc.       The  smalts  and  azures  of  commerce  are  prepared  by  fluxing  glass  -with 


Smaltite 
(Nickel 
variety, 
Chlo- 
anthite), 
Speiss 
Cobalt. 


CoAsj  or 
(CoFeNi)As., 

Very  varia- 
able. 


Chief  ore  of  cobalt.  On  charcoal  B.  B.  affords  garlic  odor  of 
arsenic;  fuses  to  magnetic  globule,  which  with  fluxes  gives  indi- 
cations of  Fe,  Co,  and  Ni.  In  closed  and  open  tube  indicates 
presence  of  arsenic.  (See  Nickel  ores.) 

This  and  the  other  ores  of  cobalt  are  usually  associated  with  ores 
of  nickel,  and  sometimes  with  those  of  silver,  lead,  and  copper. 
Sometimes  found  alloyed  in  small  quantities  with  nickel  in  many 
meteoric  irons. 


To  borax  bead  imparts  intense  sap- 
phire-blue  color  in  both  flames. 
Should  be  first  roasted.  Presence 
of  large  amounts  of  ircn  colors 
bead  green. 


Cobalt 
Glance 
(Cobalt- 
ite). 


CoAsS. 

Cobalt, 

35-5*. 


Next  in  importance  to  above. 
Cubical  crystals,  brittle. 


Reaction  for  cobalt  same  as  above. 


50 


Presence  of  cobalt  easily  recognized 
as  above. 


CHARACTERS. 


TREATMENT  WITH  ACIDS,  ETC. 


COLOR. 


LUSTRE.       STRKAK 


Fusi- 


HARD- 
NESS. 


SP.  GR. 


CRYS- 
TALLI- 
ZATION. 


MAGNETIC 

BEFORE 
OR  AFTER 


USES. 


sulphurets  should  be  roasted  on  charcoal  before  testing  with  borax,  as  in  other  metallic  species.  Dissolves  in  nitric  acid.  The 
of  the  group.  If  ferro-cyanide  of  potassium  be  added  to  solution  first  made  freely  ammoniacal,  a  green  precipitate  is  produced, 
associated  with  oxides  of  manganese.  (Missouri  and  South  Carolina.)  Largely  associated  with  arsenic,  but  the  blue  color  of  bead 
The  protoxide  has  an  intense  coloring  power  when  vitrified,  and  forms  the  basis  of  all  the  blue  colors  used  in  glass  and  porcelain 
protoxide  of  cobalt.  These  are  also  sometimes  produced  by  fusing  the  protoxide  with  pure  quartz-sand  or  carbonate  of  potassium. 


Gives  metallic  arsenic 
in  closed  tube.     Con- 
centrated   HNO3  dis- 

Tin-white to 

steel-gray, 
occasion- 

Metal-       Gray-      Easily 
lie.             black. 

5-5-6 

6.8 

I.          Slightly      See   under  heading   COBALT, 
after.            etc. 

solves  with  separation 
of  arsenious  acid,  and 

ally  irides- 
cent or 

the  solution  has  gener- 
ally a  rose-red  color. 
Yields  with  silicate  of 

grayish 
from 
tarnish. 

potassaablue  precipi- 
tate; with  chloride  of 
barium  added  to  solu- 

t 

tion,  no  precipitate. 

Gives    no     arsenic    in 
closed  tube,  but  in  open 
tube  yieldssulphurous 
fumesand  arsenic  sub- 
limate.   With  chloride 

Silver-white, 
inclining  to 
red.     Also 
grayish 
black. 

Metal- 
lic. 

Gray- 
black. 

Easily 

5-5 

6 

See    under  heading  COBALT 
etc. 

I. 

of    barium    added    to 

dilute   nitric    solution 

gives  a  heavy  deposit 
of  BaSO4. 

'1 

Cobalt 

CosOeAs» 

Bloom 
(Ery- 
thrite; 

+  8H2O. 
Cobalt, 

Peach 

blossom 

29-  5#. 

Ore). 

NAME. 


COMP.  AND 

PERCENTAGE 
OF  IMPORTANT 
CONSTITUENT. 


SPECIFIC 


GENERAL  CHARACTERS  AND  ASSOCIATIONS. 


'COBALT  AND  ITS  COMPOUNDS.— Continued. 


BEFORE  BLOWPIPE. 


Earthy 
Cobalt 
(Asbo- 
lite). 


MnOoCoO 
CuOHjO. 

Variable. 


Cobalt          (CoNi)sS4 
Pyrites        orCo3S4  = 
(Lin-  Cobalt, 

I       naeite).  57.9*. 

Variable 
quantities 
of  nickel 
and  iron 
often  re- 
place some 
of  the 
cobalt. 


Reaction  same  as  above.      Possesses  foliated  structure  like  mica.     Arsenical  fumes,  and    fuses   to   blue 


Hydrous  Cobalt  arsenate. 


Earthy  variety,  sometimes  associated  with  bog  manganese  (wad). 
Uncommon. 


Generally    found    impure,    i.e.,    admixed   with    nickel,   iron,   and 

arsenic. 
Found  sometimes  in  metamorphic  rocks  in  association  with  chal- 

copyrite,  bornite,  sphalerite,  pyrites,  etc. 


glass,  etc.  In  closed  tube  yields 
water  at  gentle  heat  and  turns  blu- 
ish. 


With  soda  on  platinum  wire  or  foil 
gives  manganese  reaction  (green); 
but  with  borax  or  salt  of  phosphorus 
gives  a  deep  blue  bead.  With  tin 
on  charcoal  in  R.  F.  sometimes  me- 
tallic copper. 

Roasted  mineral  gives  borax  bead 
sapphire-blue  color,  and  reacts  usu- 
ally for  cobalt,  nickel,  and  iron,  and 
sometimes  for  arsenic. 


52 


CHARACTERS. 

/-„„<          MAGNETIC 

COLOR.               LUSTRE.        STKEAK       £,s,         HARD-      SpGR        ^        ^ORE^                                  UsES. 

TREATMENT  WITH  ACIDS,  ETC.                                                                                                                                                         HEATING. 

In     HC1     readily    dis-     Crimson  to        Pearly        Paler           2              2             2.9            V.                            See  under  heading   COBALT, 

solves  to  rose-red  so-      peach-red         adaman-     than 

etc. 

lution.    Whenconcen-      to  greenish     tine  to        color, 

trated    appears     blue      gray.                 dull.            dry 

while  hot.                                                                          pow- 

der 

laven- 

der- 

blue. 

. 

See  under  heading  COBALT, 

Soluble    in    HC1,    with     Black.                Dull.            Earthy     Some          2.25         3.1 

etc. 

evolution  of  chlorine.                                                                    varie- 

Solution  usually  blue, 

ties 

turning     rose-red    on 

fuse. 

addition  of  water. 

Soluble  in  HNO3,  form.     Pale  steel-         Metal-        Black-     Easily        5.5           4.9            I. 

See  under  heading  COBALT, 

ing  rose-red  solution.       gray,  tar-          lie.              gray. 

* 

etc. 

nishing 

copper-red. 

1 

53 

NAME. 


COMP.  AND 

PERCENTAGE 
OF  IMPORTANT 
CONSTITUENT. 


GENERAL  CHARACTHRS  AND  ASSOCIATIONS. 


BEFORE  BLOWPIPE. 


SPECIFIC 


COPPER  AND  ITS  COMPOUNDS. 

Borax  bead  in  O.  F.  is  green  when  hot,  and  greenish  blue  when  cold;  in  R.  F.  colorless,  if  saturation  be  weak,  but  red  with 
obtained.  When  combined  with  the  oxides,  tin  and  borax  should  be  used.  When  ammonia  in  excess  is  added  to  nitric  acid 
roasted  before  making  B.  B.  test  with  borax.  For  traces  of  copper  place  drop  of  suspected  solution  on  platinum-foil;  place  in 

with  a  drop  of  HC1  and  ignited  B.  B.  color  the  flame  azure-blue. USES. — Copper  is  largely  employed  in  the  manufacture  of  many 

other  purposes.     Electrical  inventions  consume  large  and,  -with  the  advance  of  the  science,  constantly  increasing  quantities  of  this  metal. 
also  used  very  largely  in  many  important  alloys;  e.g.,  with  zinc  it  constitutes  brass,  and  with  tin  it  forms  bell-metal  and  bronze.     It  is  to 


Native.         Cu.  Ductile  and  malleable.     Readily  recognized.     Rapidly  oxidizes  su- 

perficially to  greenish  rust  upon  exposure  (Cu^OH^COs).  Lake 
Superior  most  important  region,  where  it  occurs  in  conglomerate, 
sandstone,  and  trap  rocks.  Often  results  from  oxidation  of 
other  copper  ores,  and  found  in  association  with  them. 


Fuses  readily,  covered  with  black 
oxide  (CuO).  Moistened  with  HC1 
turns  flame  sky-blue. 


Copper 

CuFeSa. 

Readily   distinguished    from    gold    and   iron    pyrites.      Fracture 

Fuses   to 

stee 

Pyrites 

uneven,  brittle.     Often  contains  a  large  quantity  of  pyrite. 

which  is   mi 

(Chal- 

Copper, 

roasted 

min 

copyrite) 

34-5*- 

copper  c 

onta 

phur    fumes 

|        with  HC1. 

Chalco- 

CusS. 

Somewhat  resembles  argentite,  but  is  not  sectile,  and  affords  dif- 

Alone   or 

on 

cite 

ferent  results  B.B.     Solution  in  HNO3    covers  knife-blade  with 

yields    a 

glc 

(Copper 

Copper, 

copper,  but  similar  solution  of  the  silver  ore  covers  copper-plate 

sulphur 

is  c 

Glance 

79-8*. 

with  silver.     This  and  the  following  ores,  except  tetrahedrite,  are 

contains 

vei 

or  Black 

usually  alteration-products  of  original  copper  pyrites. 

iron  or  s 

ilvei 

sulphide 

of  copper). 

, 

Gives  sul- 
Blue  flame 


coal   the    fine    powder 
globule   of    copper    after 
n  off.     Sometimes 


CHARACTERS. 

TREATMENT  WITH  ACIDS.ETC. 


COLOR. 


LUSTRE.        STREAK 


FUSI- 
BILITY. 


I  I  I         '          I 


HARD- 
NESS. 


SP.  GR. 


CRYS- 
TALLI- 
ZATION. 


MAGNETIC 
BEFORE 

OR  AFTER 

HEATING. 


USES. 


strong  saturation  when  hot;  metallic  copper  and  copper-red  when  cold.  On  charcoal  with  soda,  a  copper-colored  globule  is 
solution,  the  liquid  is  colored  blue;  metallic  copper  is  deposited  on  iron  wire  or  a  nail  immersed  in  this.  .Specimens  should  be 
this  a  piece  of  zinc:  a  film  of  copper  will  be  deposited  on  the  platinum-foil  at  point  of  contact.  Copper  compounds  moistened 
kinds  of  utensils,  in  the  manufacture  of  wire  and  plates  for  engraving,  etc.,  for  sheathing  ships,  for  coinage,  and  for  a  vast  number  oj 
Wire  made  from  this  metal  is  more  suitable  for  conducting  the  electrical  current  than  wire  made  from  any  other  metal  except  silver.  It  is 


a  certa  in  extent  used  in  t 

Excess  of  ammonia  to 
nitric      acid     solution 
renders     liquid     sky- 
blue   in   color.     Same 
applies  to  various  ores 
of  copper. 

Dissolves     in      HNO3, 
with  separation  of  sul- 
phur   forming    green 
solution.      Reacts  for 
sulphur,   copper,   and 
iron. 

Dissolves  in  hot  HNO3) 
with   residue   of   sul- 
phur. 

he  formation  of  blue  and  g 

Copper-red.      Metal- 
lic. 

Brass-yel-         Shining 
low,  tar-           metal- 
nishes,               lie. 
sometimes 
iridescent. 

rre  en  pigr 

Cop- 
per- 
red. 

nents. 

3-  or 

78o°C. 

3 

8.9 

See    under   heading  COPPER, 
etc. 

' 
See   under  heading  COPPER, 
etc. 

I. 

Green- 
black. 

2 

3-5-4 

4-3 

II. 

After. 

Blackish            Metal- 
lead-gray,         lic.dul!. 
Often  tar- 
nished blue 
or  green. 

Black- 
ish 
lead- 
gray, 
some- 
times 
shining 

Easily 

2-5-3 

5-5 

IV. 

See   under  heading  COPPER, 
etc. 

INAMK. 


COMP.  ANt) 

PERCENTAGE 
OF  IMPORTANT 
CONSTITUENT. 


GI-NERAL  CHARACTERS  AND  ASSOCIATIONS. 


COPPER    AND  ITS  COMPOUNDS.— Continued. 


SPECIFIC 


BEFORE  BLOWPIPE. 


Bornite        CusFeSt. 
(Varie- 
gated Copper, 
Copper  55.5; 
Pyrites 
or  Eru- 
bescite; 
Peacock 
Ore). 

Mala- 
chite 
(Copper 
Car-  Copper, 

bonate).  57-3#' 


Distinguished  from  chalcopyrite  by  its  pale  reddish-yellow  color,  Fuses  in  R.  F.  to  brittle  gray  globule 
and  its  rapidly  tarnishing  to  bluish  and  reddish  shades  of  colors.  attracted  by  magnet.  Minute 
Sometimes  admixed  with  copper  glance,  when  it  yields  50-70^  specks  from  crushed  globule  will, 
of  copper.  with  borax  bead,  give  copper  re- 

action. 


2CuO,CO», 
HaO. 


Readily  distinguished  by  green  color.     Fibrous  cleavage.     Com- 
mon with  other  ores  of  copper,  resulting  from  their  alteration. 


Decrepitates  and  blackens.  Colors 
the  flame  green.  With  borax  fuses 
to  deep  green  globule.  Ultimately 
affords  bead  of  copper  in  R.  F. 


Azurite        sCuO,  As  above.     Color  blue.     Common  with  other  ores,  etc.     Usually     Similar  to  above. 

(Blue  2CO2HaO.         accompanying    other    copper    ores,    especially    malachite    and 

Mala-  cuprite, 

chite).         Copper, 

55- IX 


66 


CHARACTERS. 

COLOR. 

LUSTRE. 

STREAK 

FUSI- 
BILITY. 

HARD- 
NESS. 

SP.  GR. 

CRYS- 
TALLI- 

MAGNETIC 

BEFORE 
OR  AFTER 

USES. 

TREATMENT  WITH  ACIDS,  ETC. 

ZATION. 

HEATING. 

Dissolves  with  separa- 

Bronze -  yel- 

Metal- 

Pale 

Easily 

3 

5 

I. 

After. 

See  under  heading   COPPER, 

tion  of  sulphur.  Part- 

low, purple 

lic. 

gray- 

etc. 

ly  soluble  in  HNO3, 

on  exposed 

ish 

when    it     reacts     as 

edges;  also 

black, 

above. 

copper  -  red 

slight- 

to brown. 

ly 

shin- 

ing. 

Gives  much    water   in 

Grass  to 

Silky  to 

Paler 

2 

3-5-4 

4 

V. 

Sometimes  it  is  cut  and  pol- 

closed    tube.       Dis- 

emerald- 

dull, 

than 

ished    for   ornamental   pur- 

solves completely, 

green. 

earthy. 

color. 

poses.     It  is  also  sometimes 

with   effervescence, 

Nearly 

used   as   a    green    pigment, 

in  HNOj,  giving  off 

opaque. 

and  in  the   manufacture  of 

CO2.      This     distin- 

Crystals 

the  various  salts  of  copper. 

guishes   it    from   all 

translu- 

other green  ores  ex- 

cent. 

cept  emerald  nickel, 

q.  v. 

' 

.'. 

As  above. 

Deep  blue. 

Pearly 

Blu- 

2 

4 

3-7 

V. 

See   under  heading  COPPER, 

and  vit- 

ish, 

etc. 

reous. 

light- 

Trans- 

er 

parent 

than 

to 

color. 

opaque. 

NAME. 


COMP.  AND 

PERCENTAGB 
OF  IMPORTANT 
CONSTITUENT. 


SPECIFIC 


BEFORE  BLOWPIPE. 


COPPER  AND  ITS  COMPOUNDS.— Continued. 

CuSiO3 


Chryso- 

colla 
(Copper 
Sili- 
cate). 


Copper, 


36*. 


Ataca- 

CuaClHsO,. 

mite 

(Chlor- 
ide of 

Copper, 
59-3*- 

Copper). 

Cuprite 
(Red 
Oxide). 

CuaO. 
Copper, 

Usually  in  form  of  incrustations,  or  filling  seams,  or  botryoidal. 
Conchoidal  fracture  and  rather  sectile.  Usually  very  impure. 

Usually  associated  with  red  copper  ore,  native  copper,  and  mala- 
chite. 


Conchoidal  fracture.  Brittle.  Found  as  aggregation  of  crystals. 
Also  massive,  granular,  fibrous,  compact,  and  as  sand.  Province 
of  Atacama,  Chile.  Also  in  Arizona. 


Commonly  crystallized  in  octahedrons,  etc.,  but  often  much 
modified.  Also  massive,  granular,  and  earthy.  Often  mixed 
with  oxide  of  iron. 


Blackens  in  R.  F.  and  yields  water 
without  melting.  With  soda  on 
charcoal  effervesces  and  yields  a 
globule  of  copper.  Easily  soluble 
in  acids.  Copper  reaction  with 
borax  and  salt  of  phosphorus. 


Gives  off  water  in  closed  tube  and 
forms  gray  sublimate.  B.  B. 
fuses  and  colors  flame  azure-blue 
with  a  green  edge. 


On  coal  yields  a  globule  of  copper. 
In  forceps  fuses  and  colors  flame 
emerald-green.  Unaltered  in  closed 
tube. 


Melac-          CuO.  A  black  powder  or  dull-black  masses  and  botryoidal  concretions 

onite  along  with  other  copper  ores.     Ordinarily  soils   fingers   when 

(Black         Copper,  massive  or  pulverulent. 

Copper  79-8jC.     Usually   found   disseminated   among   other   ores  of   copper,  and 

Ore).  sometimes   occurs    in    shining    botryoidal    concretions   or  dull 

friable  masses. 

58 


Reacts  for  copper. 


CHARACTER;-. 

TREATMENT  WITH  ACIDS,  ETC. 


Heated  in  closed  tube 
yields  water  and 
blackens  (water  20  per 
cent).  Decomposed 
without  gelatinization 
by  acids,  silica  re- 
maining behind. 

Easily  soluble  in  acids. 


Easily  and  quietly  solu- 
ble in  strong  HC1. 
Concentrated  solution 
gives  upon  addition 
of  water  a  white  pre 
cipitate  of  subchloride 
of  copper. 

The  strong  HC1  solu- 
tion gives  no  precipi- 
tate with  addition  of 
water.  Sometimes  ef- 
fervesces on  account  of 
presenceof  impurities 


fovc 

MAGNETIC 

COLOR. 

LUSTRE. 

STREAK 

FUSI- 
BILITY. 

HARD- 
NESS. 

SP.  GR. 

\^K\o- 
TALLI- 

BEFORK                                 USES. 

OR  AFTER 

ZATION. 

HEATING. 

e     Blue  to 

Vitre- 

White 

Infus. 

2-4 

2.2 

Amor- 

See under  heading   COPPER, 

d      green. 

ous, 

when 

phous 

etc. 

r      Often  black 

shining 

pure. 

d      to  brownish 

to 

a      when  im- 

earthy. 

:-      pure. 

1 

.      Bright 

Ada- 

Apple- 

2 

3-3-5 

3-7 

IV. 

See  under  heading  COPPER, 

emerald  to 

man- 

green. 

etc. 

dark  green. 

tine  to 

v  i  LI  c~ 

ous. 

. 

i-     Red,  cochi- 

Earthy, 

Brown- 

Easily 

3-5-4 

6 

I. 

See  under  heading  COPPER, 

neal-red  to 

ada- 

ish 

etc. 

n      brown-red, 

man- 

red, 

n      but  some- 

tine to 

shin- 

times 

sub- 

ing. 

e      nearly 

metal- 

black. 

lic. 

-     Iron-gray  to 

Metal- 

Gray- 

With 

3-4 

6 

V. 

See  under  heading  COPPER, 

black  to 

lic  to 

black 

diffi- 

etc. 

f      brown- 

earthy. 

culty 

black. 

{ 

3 

59 

NAME. 


COMP.  AND 

PERCENTAGE 
OF  IMPORTANT 
CONSTITUENT. 


GENERAL  CHARACTERS  AND  ASSOCIATIONS. 


COPPER  AND  ITS  COMPOUNDS.— Continued. 

Tetra-  Cu8S7Sba.  Often  a  valuable  ore  of  silver,  q.  v.\  less  frequently  an  ore  of 
hedrite  Very  vari-  copper  commercially  speaking.  Several  varieties  which  show 
(Gray  able.  different  reactions.  A  closely  related  form  is  tennantite,  sub- 

Copper),  stantially  CugAs2ST,  the  antimony  being  replaced  by  arsenic.    In 

Copper,  this  the  copper  is  often  partially  replaced  by  silver  (the  "gray 

52.  i#.         copper"  of  local  miners)  in  which  the  percentage  of  silver  some- 
times reaches  as  much  as  14  per  cent. 

This  mineral  sometimes  contains  zinc  and  silver,  and  occasionally 
mercury.     It  is  often  associated  with  chalcopyrite,  pyrite,  sphal- 
erite, galena,  and  various  other  silver,  lead,  and  copper  ores; 
x"  '  also  siderite. 


SPECIFIC 


BEFORE  BLOWPIPE. 


The  roasted  mineral  gives  on  char- 
coal, after  long  heating  a  globule 
of  copper;  often  also  reacts  for  iron, 
antimony,  arsenic,  and  mercury. 


Corun- 
dum 
(Emery, 
common 
granular 
variety 
colored 
black  by 
magnet- 
ite). 


Very  hard,  being  next  in  hardness  to  diamond.  Sub-varieties  are 
sapphire,  ruby,  amethyst  (oriental),  topaz,  and  emerald,  which  are 
transparent  or  translucent  and  very  valuable  as  gems. 

Usually  associated  with  some  member  of  the  chlorite  group,  and 
a  series  of  aluminous  minerals  in  part  produced  from  its  altera- 
tion. 


Slowly  but  perfectly  soluble  in  salt  of 
phosphorus  io  a  clear  glass.  When 
finely  powdered  and  after  long 
heating  with  cobalt  solution  gives 
a  fine  blue  color. 


60 


CHARACTERS. 

TREATMENT  WITH  ACIDS,KTC. 


COLOR.  LUSTRE.       STREAK 


Fusi-        H> 


CRYS- 
TALLI- 
ZATION. 


MAGNETIC 
BEFORE 

OR  AFTER 

HEATING. 


USES. 


Reacts  for  copper,  sul- 

Flint-gray to     Dark 

Steel- 

i 

3-5- 

4.7            I.                           See   under  heading  COPPER, 

phur,  and    antimony. 

iron-black.        gray. 

gray 

4-5 

etc. 

Frequently  copper  re- 

Metal- 

to 

placed    by    iron    and 

lic  to 

black 

zinc,  as  well  as  silver 

splen- 

and 

and    mercury,    while 

dent. 

to 

J^^\^>  R  A7?*^v 

antimonyis  frequently 

brown 

replaced     by    arsenic 
and  bismuth.    Decom- 

and 
cher- 

( UNIVERSITY  J 

posed   by   nitric   acid 

ry- 

^^                 OF                    tf 

with  separation  of  sul- 

red. 

^^^UFORM^C^ 

phur     and     antimony 

trioxide. 

Not   affected   by   acids 

Blue,  red, 

Often 

Same 

Infus. 

9 

4 

III. 

Corundum,    and   more  espe- 

or  by  heat,   but   ren- 

purple, yel-      bright, 

as                                                                                                cially     the     impure     form, 

dered    soluble  by  fu- 

low, green;      vitre- 

color.                                                                                         crushed  to  different  degrees 

sion   with    potassium 

when  less          ous. 

of  fineness,  makes  the  abrad- 

bisulphate. 

pure  gray- 

ing  and   polishing  material 

brownish, 

known    in  commerce   as 

light  blue 

* 

emery.     This  is  used  either 

and  black. 

as  a  powder  or  mixed  with 

other  materials  to  make   it 

1 

cohere;  it  is  made  into  va- 

rious   shapes     for    cutting, 

abrading,    and    polishing  — 

e.g.,  emery-wheels,  etc. 

61 

NAME. 


Dia- 
mond. 


Emerald 
(Beryl). 


Epidote. 


COMP.  AND 

PERCENTAGE 
OF IMPORTANT 
CONSTITUENT. 

c. 


Be,AlaSuO18 

Approx. 
Silica,  67^. 
Alumina, 

19*- 

Berylla  or 
Glucina, 
-.     '       14*. 

Very  vari- 
able. 


GENERAL  CHARACTERS  AND  ASSOCIATIONS. 


Characterized  by  its  extreme  hardness.  Brittle.  Valuable  as  a 
gem  and  for  cutting  tools. 

Usually  occurs  in  alluvial  or  driftal  deposits  in  gravel,  sand,  or 
clay,  or  rarely  in  consolidated  conglomerates  or  grits,  associated 
with  quartz,  gold,  platinum,  octahedrite,  rutile,  hematite,  ilmen- 
ite,  topaz,  corundum,  tourmaline,  garnet,  etc.  Supposed  to  be 
of  original  vegetable  origin,  the  carbon  having  been  dissolved 
and  redeposited  in  some  way  not  understood. 


SPECIFIC 


BEFORE  BLOWPIPE. 


At  very  high  temperatures  out  of  con- 
tact with  the  air  it  is  transformed 
into  a  kind  of  coke,  etc.,  etc.  (See 
Dana's  Min.,  pp.  4-6.) 


The  distinctive  characteristic,  bright  emerald  green  color,  is  sup- 
posed to  be  due  to  the  presence  of  traces  of  chromium.  Its 
hardness  distinguishes  it  from  apatite,  and  this  character  as  well 
as  the  formation  of  the  crystals  from  green  tourmaline. 

Found  in  granite,  gneiss,  mica  schist,  dolomite,  with  phenacite, 
chrysoberyl,  apatite,  rutile,  etc.  Widely  distributed,  but  Muso 
in  New  Granada,  East  Cordillera  of  the  Andes,  is  the  most  cele- 
brated locality.  North  Carolina  has  furnished  some  fine  gems. 
The  oriental  emerald  of  jewelry  is  emerald-colored  sapphire. 

A  lime,  iron,  aluminum  silicate.  Quite  hard  and  somewhat  harder 
than  chlorite,  for  which  it  sometimes  maybe  mistaken.  A  rather 
common  rock  constituent. 

Associated  usually  with  quartz,  calcite,  pyroxene,  feldspar,  chlo- 
rite, hornblende,  garnet,  magnetite,  pyrites,  etc.,  especially  in 
old  and  highly  metamorphic  formations.  Sometimes  also  in 
eruptive  rocks  and  in  vein  deposits. 

63 


Alone  unchanged,  or,  if  clear,  be- 
comes milky  white  and  clouded; 
after  protracted  heating  the  edges 
of  splinters  become  rounded.  A 
small  percentage  of  water  and  or- 
ganic matter  lost  upon  ignition,  but 
color  usually  retained. 


Fuses  with  intumescence  to  a  slaggy 
mass,  dark  brown  in  color,  which 
is  generally  magnetic. 


CHARACTERS. 

TT   .  ~- 

1 
CRYS-       MAGNETIC 

COLOR.               LUSTRE. 

STREAK                                           SP.  GR.       TALLI-         BEFORE 

USES. 

TREATMENT  WITH  ACIDS,ETC. 

[__]_                                                      ZATION-       HHA™ 

Unaffected  by  acids  or     Colorless   to     Ada- 

Infus.         10           3.5      ,      I.                           Diamonds,  besides   being 

alkalies,                                 black.                 man- 

largely    used     and     highly 

tine. 

1                        nrized    as    iewelrv.    are    em- 

j  • 

ployed  for  cutting  glass,  for  which  purpose  the 

natural   edge    of    a   crystal    is    best   adapted. 

Compact    and   amorphous  varieties  known  as 

1 

bort  and  carbonado  are  employed  for  cutting 

purposes  in  jewelry.     Bort  is  used  as  a  powder 

for  cutting  diamonds  and  other  hard  stones,  and 

very  frequently  when  set  in  the  edges  of  boring 

tools  (diamond  drills)  the  whole  stone  or  frag- 

ments are  used  for  drilling  holes  in  hard  rock. 

Unacted  upon  by  acids.     Brigh 

t                Vitre- 

White        5.5           7.5        2.6-2.8       III.                           Used   as  a  eem   when   clear 

emerald-            ous, 

and  free  from  flaws. 

green.                trans- 

parent 

~ 

to 

trans- 

lucent. 

Partly  decomposed  by     Pistachio-         Vitre- 
HC1,    but   when    pre-      green,                ous, 
viously  ignited,   gela-      brown,  yel-       trans- 

Uncol-         3            6-7 
ored, 
gray- 

3-5 

V. 

tinizes  with  acid.   De-      low,  green-       lucent 

ish. 

composed    on    fusion       ish  black,           to 

with  alkaline  carbon-       gray,  etc.          opaque. 

ates.     (Dana.) 

«3 

. 

NAMB. 


Feld- 
spars. 
Common 
rock  con- 
stituents, 
espe- 
cially of 
igneous 
rocks. 


Fire-clay. 


COMP.   AND 

PERCENTAGE 
OF  IMPORTANT 
CONSTITUENT. 

Essentially 
silicates  of 
alumina, 
with  vari- 
able pro- 
portions of 
silicates  of 
potash, 
soda,  mag- 
nesia, and 
lime. 


GENERAL  CHARACTERS  AND  ASSOCIATIONS. 


Varieties:  Orthoclase. — Potash  or  common  variety.  Cleaves  in  two 
directions  at  right  angles.  All  other  feldspars  cleave  at  oblique 
angles.  Found  in  crystalline  rocks,  being  a  constituent  of  gran- 
ite, gneiss,  syenite,  etc.,  and  also  of  the  eruptive  rocks — por- 
phyry, trachyte,  phonolyte,  etc. 


SPECIFIC 


BEFORE   BLOWPIPE. 


Fuses  quietly.  Colors  flame  violet  or 
lavender  (potassium).  (See  Flame 
Colors.)  Some  specimens  give  soda 
flame. 


Oligoclase.  —  Soda-lime   variety.     Occurrence   much  the  same   as 
above. 


Fuses  quietly.  Colors  flame  orange- 
yellow  (sodium).  (See  Flame 
Colors.) 


Albite. — Soda   variety.     Usually   distinguishable   from  orthoclase     Fuses  quietly.     Colors   flame   an   in- 


by  its  greater  whiteness.     Occurrence  much  the  same  as  above. 

The  above  are  very  variable,  and  distinguished  from  quartz  by 
their  inferior  hardness,  the  shape  of  the  crystals,  and  other 
well-known  physical  characteristics. 


tense    orange-yellow.     (See    Flame 
Colors,  Appendix.) 


The  clay  used  for  fire-brick  should  be  a  nearly  pure  silicate  of  alumina  and  free  from  lime  and  the  alkalies.  Ctour- 
clay  used  for  making  bricks  vary  very  widely  in  composition  and  in  the  results  obtained.  Grades  insensibly  into 
association  with  coal,  is  in  making  fire-bricks  and  retorts  for  blast-furnaces,  for  other  metallurgical  works,  and  for 
made  in  large  quantities,  and  are  used  for  fire-proof  partitions,  etc.,  for  safe-  and  refrigerator-linings,  and  for  other 
of  fire-clays  are  also  largely  used  by  paper-manufacturers  in  glazing  and -weighting  paper.  A  considerable  quantity  is 


CHARACTERS. 


COLOR. 


LUSTRE.       STREAK 


FUSI- 
BILITY. 


HARD- 
NESS. 


SP.  GR. 


TREATMENT  WITH  ACIDS,  ETC. 

Not     acted     upon     by     Colorless,         Vitre- 
acids.  pale  yellow,      ous  to 


CRYS- 
TALLI- 
ZATION. 


MAGNETIC 

BEFORE 
OR  AFTER 

HEATING. 


Uncol- 
ored. 


6  2.5  V. 


USBS. 


The  chief  use  of  feldspar  is 
in  the  manufacture  of  cer- 
tain kinds  of  pottery,  for 
which  the  purer  grades  are 
very  desirable.  Orthoclase 
is  used  in  a  finely  powdered 
state  as  a  glaze  for  porcelain 
and  to  a  small  extent  in 
jewelry,  though  sun  s  t on  e 
(aventurine  feldspar)  and 
moonstone  are  mostly  oligo- 
clase. 

When  found  in  abundance  it 
is  used  like  the  above  in  the 
manufacture  of  the  finer 
kinds  of  pottery. 


bridge  clay  contains  from  fio#  to  70^  silica  and  from  20^  to  30^  alumina,  with  traces  only  of  iron  and  lime.     Of  course  the  kinds  of 

pure  kaolin,  q.  v. USES. —  The  principal  use  of  the  purer  and  whiter  clays,  and  the  clay,  if  suitable ,  found  so  generally  in  stratified 

gas-works.  Refractory  clay  is  also  used  for  making  sewer-pipe,  water-pipe,  and  chimney-tops.  Porous  brick  and  terra-cotta  lumber  are 
purposes  where  nonconducting  and  fire-probf  materials  are  required.  Roofing-tiles  and  hollow  bricks  are  also  made.  The  purer  forms 
used  in  the  manufacture  of  alum,  Orditfary  building-brick  is  made  from  the  much  more  impure  and  common  varieties  of  clay. 


white,  nesn-      pearly. 

^ 

red,  gray, 

green. 

Not     acted     upon     by 

White  and         Vitre- 

Uncol- 

3-5 

6-7 

2.6 

VI. 

acids. 

flesh-red.           ous, 

ored. 

etc. 

Not     acted     upon  ;  by 
acids. 

Colorless,          Vitre- 
white,  dull        ous, 

Uncol- 
ored. 

4 

6-6.5 

2.6 

VI. 

green.                etc. 

^ 

- 

65 


NAME. 


Fluor- 
spar 
(Fluor- 
ite). 

Common 
vein- 
stone. 


COMP.  AND 
PERCENTAGE 
OF  IMPORTANT 
CONSTITUENT. 

CaFa. 


GENERAL  CHARACTERS  AND  ASSOCIATIONS. 


Characteristic  phosphorescence  on  heating  is  distinguishing  feat- 
ure. It  is  valuable  as  a  fluxing  material,  for  which  purpose  it 
is  often  preferred  to  carbonate  of  lime.  Not  very  abundant  in 
the  United  States.  Frequently  occurs  in  veins  in  connection 
with  and  as  the  gangue  of  many  of  the  metallic  ores,  especially 
of  lead.  The  veins  may  traverse  nearly  any  kind  of  ore,  but 
fluor-spar  is  usually  found  in  gneiss,  mica-slate,  clay-slate,  lime- 
stone, sandstones,  and  sometimes  in  volcanic  breccia. 


SPECIFIC 


BEFORE  BLOWPIPE. 


When  gently  heated  gives  out  green- 
ish or  purplish  phosphorescence 
temporarily  and  colors  flame  red. 
Turns  white  and  decrepitates,  and 
ultimately  fuses  to  an  enamel  which 
gives  an  alkaline  reaction  on  test- 
paper. 


Fuller's 
Earth. 


An  earthy  hydrated  silicate  of  alumina,  composed,  when  pure,  of  45^  silica,  20%  to  25^  alumina  and  water.     Like 
fulling  or  cleansing  of  -woollen  fabrics  and  cloth,  since  it  was  an  excellent  absorbent  of  the  grease  and  oil  contained  in  them. 


Garnet.         Exceed- 
Common      ingly 
rock  variable, 

constitu- 
ent. 


Alumina,  iron,  and  chrome  garnets,  all  brittle.  Generally  impure 
and  porous. 

Common  in  mica  schist,  gneiss,  syenite  and  chlorite  schist,  and 
other  metamorphic  rocks.  Also  in  crystalline  limestone,  dolo- 
mite, granite,  etc.,  sometimes  in  serpentine  and  volcanic  rocks, 
etc. 


Most  garnets  fuse  easily  to  a  brown 
or  black  glass,  but  fusibility  varies, 
and  chrome  garnet  is  almost  infusible. 
(Compare  cassiterite.) 


66 


CHARACTERS. 

TREATMENT  WITH  ACIDS,  ETC. 

In  closed  tube  decrepi- 
tates   and     generally 
phosphoresces.  Fused 
with  bisulphate  of  po- 
tassa    in    closed   tube 
yields  vapors  of    hy- 
drofluoric acid,  which 
corrode  glass.     Same 
effect     when     treated 
with  sulphuric  acid. 

COLOR. 

LUSTRE.       STREAK 

Fusi-' 

BILITY. 

HARD- 
NESS. 

SP.  GR. 

CRYS- 
TALLI- 
ZATION. 

MAGNETIC 

BEFORE 
OR  AFTER 

HEATING. 

USES. 

Fluor-spar    is    used    and    is 
very  desirable  as  a  flux  in 
metallurgical    processes,  as 
in  the    reduction   of  alumi- 
num; also  largely  in  making 
glass,  in  the  manufacture  of 
hydrofluoric  acid,  in  making 
paints,  enamels,  and  mineral 
wool.    Sometimes  made  into 
very     beautiful    vases    and 
ornamental  objects. 

used   as   an    absorbent   in   the 

' 
The  fine  specimens  are  prin- 
cipally used  as  gems.     The 
gem  known  to  the  ancients 
as  "carbuncle"  —  and   to    a 

All  colors. 

Vitre- 
ous, 
trans- 
parent 
to  sub- 
trans- 
lucent. 

Whit- 
ish. 

3 

4 

3-2 

I. 

other  soft,  aluminous    1 
Other  substances  have  bee 

Not     decomposed     by 
HC1,   but   if   first    ig- 
nited, then  pulverized 
and  treated  with  acid, 
they  are  decomposed, 
and    the    solution 
usually  gelatinizes 
when  evaporated. 

ninerals,  abs 
i  substituted,  ) 

Red  to  cin- 
namon- 
brown, 
black, 
green, 
emerald- 
green,  but 
rarely 
colorless. 

orbs  grease 
'owever,  an 

Vitre- 
ous. 

T 

JSES.  —  Fuller's    earth    was  formerly   largely 

d  the  con. 
White. 

sumption  I 

Va- 
rious, 

3-6, 
most 
varie- 
ties 

easily 

Rf 

las  fallen  off  greatly  in  consequence. 
7            3-4             I- 

certain  extent   the    term  is  used   at  the  present  day  —  is  simply 
a  deep   red    variety   of  garnet  cut  in  a  certain  fashion.     The 
chief  use  of  the   varieties  not  suitable  for  gems,  especially  the 
variety  almandite,  is  in  the  manufacture  of  sand-paper  or  garnet- 
paper.     It  is  utilized  for  abrasive  purposes  in  the  manufacture 
of  boots  and  shoes,  and  also  to  a  less  degree  in  the  woodwork- 
ing industry.      For  metals   emery   is  usually  preferred.     The 
garnet  used   in  the  manufacture  of  garnet-paper  is  found  to  be 
harder,  sharper,  and  more  durable  than  quartz,  and  is  preferred 
to  quartz  for  this  purpose,  though  costing  many  times  as  much. 

1 

NAME. 


COMP.  AND 

PERCENTAGE 
OF  IMPORTANT 
CONSTITUENT. 


GENERAL  CHARACTERS  AND  ASSOCIATIONS. 


SPECIFIC 


BEFORE  BLOWPIPE. 


GOLD  AND  ITS  COMPOUNDS. 

Gold  may  be  generally  recognized  by  its  physical  characters — color,  lustre,  malleability,  and  specific  gravity.  When  a  gold 
regia.  If  this  solution  be  dropped  on  to  a  filter-paper  and  one  drop  of  stannous  chloride  be  added,  a  purple-red  color  is  obtained. 
precipitate  being  dissolved  and  tested  with  stannous  chloride,  it  is  separated  from  the  easily  volatile  metals  by  simply  heating  on 
cupellation.  The  copper  is  absorbed  into  the  cupel  with  the  lead,  while  the  silver  remains  alloyed  with  the  gold.  If  the  globule 
of  silver,  which,  after  fusing  on  charcoal  in  O.  F.,  will  impart  an  opaline  character  to  the  cool  bead.  If  it  be  more  of  a  silver-white 
with  nitric  acid  by  application  of  heat.  The  silver  is  thus  dissolved,  and  the  gold  remains  as  a  dark  powder  or  spongy  mass.  If 
native  metal.  Iron  pyrites  is  frequently  found  combined  with  a  small  percentage  of  gold,  but  the  other  minerals  with  which  it  is 


Fuses   easily. 
fluxes. 


Is    not    acted   on   by 


Native.        Au.  Easily  recognized  by  its  physical  properties.     No  cleavage,  hackly 

fracture,  and  great  malleability  and  ductility. 
The  association  and  distribution  of  native  gold  and  its  ores 
have  to  be  considered  under  two  heads:  (a)  as  it  occurs  in 
mineral  veins,  and  (6)  as  it  occurs  in  alluvial  or  other  superficial 
deposits  which  are  derived  from  the  erosion  of  the  region  con- 
taining these  mineral  veins  or  contact  deposits.  With  regard  to 
the  first  it  is  found  generally  in  quartz  veins  or  reefs  travers- 
ing slaty  or  crystalline  rocks,  schists,  talcose  schists,  and  many 
kinds  of  eruptive  rocks.  It  is  most  frequently  associated  with 
quartz  and  iron  pyrites,  but  is  also  very  often  found  in  connec- 
tion with  galena,  blende,  magnetic  and  specular  oxide  of  iron, 
and  other  minerals,  and  also  very  often  with  silver  ores.  It  is 

quite  frequently  associated  with  the  tellurium  minerals,  q.  v.     It 

may  be  said,  generally  speaking,  that  gold  is  usually  found  in  rocks  of  a  silicious  character,  and  is  not 
often  found  in  basic  rocks,  although  there  are  many  exceptions  to  this  rule.  With  regard  to  the 
second  class  (alluvial  or  drift  deposits,  known  as  "placers")  the  associated  minerals  are  generally  those 
of  great  density  and  insolubility,  such  as  minerals  of  the  platinum  group,  tin-stone,  chromic  iron  ore, 
sometimes  precious  stones,  etc.,  etc.,  admixed  with  quartzose  pebbles  or  sand. 

68 


CHARACTERS. 


TREATMENT  WITH  ACIDS.ETC. 


F 

IS 

HARD- 

,ETC. 

11 

n 

1 

NESS. 

CRYS- 

TALLI- 


MAGNKTIC 

BEFORE 
OR  AFTER 

HEATING. 


USES. 


compound  is  heated  on  a  carbonized  match  or  charcoal  in  R.  F.,  a  yellow  malleable  bead  is  obtained,  which  dissolves  in  aqua 
Gold  can  be  readily  detected  in  its  solutions,  inasmuch  as  it  is  obtained  in  a  metallic  state  by  reducing  agents.  The  well-washed 
charcoal  in  O.  F.  If  associated  with  copper  or  silver,  it  must  be  fused  with  a  large  excess  of  pure  metallic  lead  and  subjected  to 
is  quite  yellow,  this  is  a  proof  that  but  little  silver  is  present.  It  is  then  to  be  tested  with  salt  of  phosphorus  to  prove  the  presence 
color,  the  amount  of  gold  will  be  small,  and  in  order  to  prove  its  presence  and  approximate  quantity  the  globule  must  be  digested 
this  powder  or  mass  be  washed  and  fused  with  borax  on  charcoal,  it  will  yield  a  globule  of  metallic  gold.  The  chief  source  is  the 
associated  are  rare. USES. —  Used  as  a  money  metal,  for  gilding,  for  jewelry,  and  for  a  vast  number  of  ornamental  objects. 


Insoluble  in  any  single 
acid,  but  readily  in 
nitro-hydrochloric. 


Yellow, 
rarely 
orange-red, 
and    inclin- 
ing   to   sil- 
ver-white. 


Dull 
metal- 
lic. 


Like 
color. 


2-5-3       2.5-3 


See  under  heading  GOLD,  etc. 


NAME. 


COMP.  AND 
PERCENTAGE 
OF  IMPORTANT 
CONSTITUENT. 


GENERAL  CHARACTERS  AND  ASSOCIATIONS. 


SPECIFIC 


BEFORE  BLOWPIPE. 


COMPOUNDS.— Continued. 


Aurifer- 

Variable. 

ous  Iron 

Pyrites, 

etc.  (See 

Pyrite.) 

Sylvan- 

(AgAu)Te2 

ite,  etc. 

(Tellu- 

Gold, 

ride  of 

24-5*. 

Gold.) 

Silver, 

13-4*. 

.and   varia- 

ble,  some- 

times little 

or  no  silver 

present. 

Gold  is  found  intimately,  but  usually  in  very  small  quantities,  associated  with  pyrites,  but  the  best  opinion 
alteration.  In  fact,  they  are  found  imbedded  in  each  other,  but  with  no  further  relation  than  that  they 
chalcopyrite,  marcasite,  etc.,  when  associated  with  gold. 


A  telluride  of  gold  and  silver  in  which  the  proportion  of  gold  and 
silver  is  nearly  equal.  Transylvania,  California,  and  Colorado. 

Calaverite  is  a  variety  in  which  the  proportion  of  gold  to  silver  is 
6  to  i. 

Nagyagite,  another  variety,  is  a  sulpho-telluride  of  lead  and  gold 
and  antimony. 

At  Cripple  Creek,  Colo.,  very  little  silver  is  present,  the  com- 
bination being  simple  telluride  of  gold.  The  associated  minerals 
are  usually  quartz,  pyrites,  sometimes  fluor-spar,  etc.,  etc. 


After  long  heating  gives  a  yellow 
malleable  metallic  globule.  On  coal 
fuses  to  a  dark  gray  globule,  de- 
positing at  same  time  a  white  coat- 
ing, which  in  R.  F.  disappears, 
tinging  flame  bluish  green. 


CHARACTERS. 


COLOR. 


LUSTRE.       STREAK 


TREATMENT  WITH  ACIDS,  ETC. 


FUSI- 
BILITY. 


HARD- 
NESS. 


SP.  GR. 


CRYS- 
TALLI- 
ZATION. 


MAGNETIC 
BEFORE 

OR  AFTER 

HEATING. 


USES. 


is  that  there  is  no  chemical  combination  of  the  two.     It  occurs  in  pyrites  or  attached  to  pyrites  or  the  oxide  resulting  from  its 
were  deposited  together,  one  on  the  other.     This  is  also  true  of  the  other  sulphides,  such  as  galena,  zinc  blende,  arsenopyrite, 


Incompletely  soluble  in 
HNO3.  Soluble  in 
aqua  regia,  with  sep- 
aration of  chloride  of 
silver.  In  open  glass 
tube  yields  a  white 
sublimate  of  tellurium 
dioxide  which  is  gray 
near  the  assay,  and 
which,  when  played 
upon  by  flame,  fuses 
to  transparent  drops. 


Steel-gray 
to  silver- 
white,  rare- 
ly brass- 
yellow. 


Metal- 
lic, bril- 
liant. 


Steel- 
gray 
and 
like 
color 


Easily      1.5-2 


V. 


See  under  heading  GOLD,  etc. 


71 


NAME. 


CoMP.  AND 

PERCENTAGE 
OF  IMPORTANT 
CONSTITUENT. 


Graphite     C. 


GENERAL  CHARACTERS  AND  ASSOCIATIONS. 


Resembles  molybdenite  (q.  z/.),  but  differs  in  being  unaffected  by 
the  blowpipe  and  acids,  and  greatly  in  specific  gravity.  The 
same  characters  distinguish  the  granular  varieties  from  any 
metallic  ores  they  resemble. 

Usually  found  in  very  old  crystalline  rocks  of  sedimentary  origin 
in  irregularly  bedded  veins  or  masses,  but  is  often  found  as  a 
constituent  of  mica  schist  or  gneiss,  and  sometimes  of  crystalline 
limestone.  Sometimes  found  disseminated  through  these  rocks 
as  foliated  laminae  or  scales,  and  occasionally  in  the  older  sand- 
stone. Being  derived  from  organic  matter,  it  is  naturally  found 
in  rocks  of  an  originally  sedimentary  character,  though  these 
are  now  usually  greatly  metamorphosed.  The  so-called  vein 
graphite  is  usually  associated  with  calcite  and  quartz.  Pyroxene, 
mica,  and  apatite  are  sometimes  found  with  it. 


SPECIFIC 


BEFORE  BLOWPIPE. 


Very  soft.  Soils  the  fingers  and  feels 
greasy.  Absolutely  infusible  B.  B. 
If  held  in  zinc  forceps  and  dipped 
into  solution  of  sulphate  of  copper, 
becomes  quickly  covered  with  cop- 
per. At  a  high  temperature  burns, 
but  not  more  easily  than  diamond, 
y.  v. 


Halite          NaCl.  Crystalline  form  of  common  salt.     Distinguished  by  its  solubility     Crackles  or  decrepitates  when  heated. 

(Rock  and  saline  taste.     Cubic  crystals.     Furnishes  the  greater  part  of         Fuses  easily,  coloring  flame  a  deep 

Salt)  Chlorine,  the  supply  of  salt.  yellow, 

(mas-  39-4#-     Occurs  in  extensive  but   irregular  beds  in  many  stratified  forma- 

sive).  Sodium,  tions  usually  associated  with  gypsum,  anhydrite,  calcite,  clays, 

6o.6«{.         or  sandstone.     In  Chile  often  associated  with  the  nitrate  of  soda . 

deposits.     Common   salt  is  often  found  covering  large  areas  representing  the  drying  up  of  salt  lakes; 

also  as  an  efflorescence   in  arid  and   semi-arid  regions,  and  also  in  solution  forming   salt  springs  or  in 

the  water  of  the  ocean  and  all  inland  salt  seas. 

72 


CHARACTERS. 


TREATMENT  WITH  ACIDS,ETC. 


COLOR. 


LUSTRE.        STREAK 


FUSI- 
BILITY. 


HARD- 
NESS. 


SP.  GR. 


MAGNETIC 
BEFORE 

OR  AFTER 

ZATION-       HEATING. 


CRYS- 

TALLI- 


When  treated  in  a  plat- 
inum spoon  with  nitre 
deflagrates,  affording 
carbonate  of  potassa, 
which  effervesces  in 
acids.  Unaffected  by 
acids. 

Iron-black 
to  dark 
steel-gray. 

Metal- 
lic, 
some- 
times 
dull 
earthy 

Black 

Infus. 

1-2 

2-2.2 

III. 

C 

'••    ."  '"'• 

, 
i 

Soluble  in  3  parts  of 
water.  With  nitrate 
of  silver,  white  pre- 
cipitate of  silver  chlo- 
ride. 

Colorless, 
white,  yel- 
low, red, 
bluish, 
purple. 

Vitre- 
ous. 

White. 

Easily 

2.5 

2.15 

I. 

1 

1 

i 
i 

i 

3 

USES. 


Graphite  is  extensively  em- 
ployed as  a  lubricant  in  ma- 
chinery, for  making  refrac- 
tors crucibles,  for  stove 
polish,  paints,  in  the  manu- 
facture of  lead-pencils,  and 
generally  in  the  manufacture 
of  refractory  articles  and 
somewhat  in  the  manufac- 
ture of  electrical  supplies. 
By  far  the  most  part  is  em- 
ployed in  the  manufacture  of 
crucibles,  after  which  comes 
the  consumption  for  stove 
polish,  for  which  an  inferior 
grade  of  mineral  suffices. 
The  amount  used  for  lead- 
pencils  is  comparatively 
small,  but  the  best  quality  is 
required. 

This  mineral  is  the  chief 
source  of  common  salt.  It 
is  not  considered  necessary 
to  mention  the  manifold 
uses  to  which  this  compound 
is  put. 


NAME. 


Horn- 
blende 
(Amphi- 
bole). 

(Com- 
mon 
rock 

constitu- 
ent.) 


COMP.  AND 

PERCENTAGE 
OF  IMPORTANT 
CONSTITUENT. 

Essentially 
bisilicates  of 
various  pro- 
toxides and 
sesquioxides. 
The  protox- 
ides may  be 
magnesia, 
lime,  soda, 
potash,  and 
the  protox- 
ides of  iron 

and  man-      . 

ganese.    The  sesquioxides  are  alumina  andl 
the  peroxides  of  iron  and  manganese. 


SPECIFIC 


GENERAL  CHARACTERS  AND  ASSOCIATIONS. 


Numerous  compounds,  which  it  is  not  necessary  to  mention.  Very 
tough.  Compare  pyroxene,  to  which  it  is  closely  allied,  in  com- 
position as  well  as  appearance.  Massive  (hornblende  schist). 
Chief  varieties  are  tremolite  and  actinolite,  to  which  when  fibrous 
the  name  asbestus  is  often  given;  also  referred  to  as  mountain 
leather,  mountain  paper,  mountain  cork,  or  mountain  -wood.  (See 
Asbestos.) 

Occurs  abundantly  in  the  older  metamorphic  rocks,  such  as  in 
many  crystalline  limestones,  granites,  and  schistose  rocks.  It 
occurs  sparingly  in  serpentine  and  igneous  rocks. 


BEFORE   BLOWPIPE. 


Swells  up  and  fuses  with  effervescence 
to  a  black  or  grayish  glass. 


HYDROCARBONS. 

Compounds  of  carbon,  hydrogen,  and  oxygen.  These  compounds  are  numerous,  and  form  a  great  variety  of  economically 
under  their  proper  heads.  For  sake  of  distinguishing  between  them  the  various  coals  are  placed  in  a  separate  division,  although 
quantities  of  paraffin,  while  this  can  be  said  of  only  a  few  of  the  coals.  While  the  latter  chemically  considered  possess  many 

a.  Fixed  A  peculiar  hard  pitchlike  material,  somewhat  resembling  coal.  Some  varieties  soften  a  little  in  boiling 

Solids.  carbon  water,  and  all  are  but  slightly  soluble  in  camphene.  Not  as  fusible  or  as  soluble  in  benzene  or  ether  as 

(about  86#)  asphaltum,  but  shows  incipient  fusion  in  candle  flame.  The  same  may  be  said  of  the  following  varieties, 

Albertite.  much  which  differ  from  each  other  chiefly  in  the  amount  of  oxygenation  which  they  have  undergone,  which 

higher  fact  has  had  an  important  bearing  upon  their  physical  properties.     They  pass  from  one  into  the  other 

than  in  the  by  insensible  gradations.      Albertite  is  usually  extremely  brittle,  with  very  distinct  conchoidal  fracture. 

following.  Occurs  filling  irregular  fissures  in  rocks  of  the  Subcarboniferous  or  Lower  Carboniferous  age  in  Nova  Scotia. 


CHARACTERS. 
TREATMENT  WITH  ACIDS,  ETC. 

Not     acted     upon     by 
acids,    or    only    very 
slightly. 

COLOR.               LUSTRE. 

STREAK 

FUSI- 
BILITY. 

HARD- 
NESS. 

SP.  GR. 

CRYS- 
TALLI- 
ZATION. 

V. 

MAGNETIC 

BEFORE 
OR  AFTER 

HEATING. 

Generally          Vitre- 
green  to             ous, 
black.                  silky. 
Sub- 
trans- 

Uncol-       2.5 
ored 
or 
paler 
than 

5-5 

3 

lucent 

color. 

to 
opaque. 

. 

USES. 


important  gaseous,  liquid,  and  solid  products,  the  composition  and  characters  of  the  more  prominent  among  which  are  stated 
they  are  also  oxygenated  hydrocarbons,  one  point  of  difference  being  that  the  substances  here  enumerated  generally  yield  large 
characteristics  in  common  with,  they  differ  widely  in  physical  and  in  other  respects  from,  the  following  less  well  known  varieties: 


Some  varieties  are  not     Lustrous            Bril-            Black      Imper-        1.5          I.OQ       Amor- 

at  all  soluble,  others      jet-black.          liant  to                       feet.                                       ohous 

partially  soluble  in  oil                                   dull, 

of   turpentine.      Soft- 

vitre- 

ens a  little  in  boiling 

ous. 

water. 

• 

K 

NAME. 


COMP.  AND 
PERCENTAGE 
OF  IMPORTANT 
CONSTITUENT. 


GENERAL  CHARACTERS  AND  ASSOCIATIONS. 


SPECIFIC 


BEFORE  BLOWPIPE. 


HYDROCARBONS.— Continued 


f     Graham-      More  vola-      Much  like  albertite,  but  differs   from   it    in    being   entirely  soluble   in  camphene;   also    harder.      Melts 


ite. 


Uintahite 
or  Gil- 
sonite. 


tile  mat- 
ter (illu- 
minating 
gas) than 
in  albertite. 


only  imperfectly  when  heated. 
Occurrence  much  the  same  as  the  foregoing,  in  West  Virginia. 


Related  to  albertite,  but  tougher,  with  fracture  conchoidal,  and  having  very  different  properties.     Fuses 

easily  in  candle  flame. 
Occurs  in  true  fissure  veins  traversing  sandstones  and  shales  in  much  the  same  manner  as  the  above, 

in  Utah,  etc. 


Ozoker- 
ite. 


Simple  hy- 
drocarbon 
contain- 
ing no 
oxygen,  a 
paraffin. 


Like  wax  or  spermaceti  in  consistency.  It  and  kindred  substances  often  referred  to  as  "earthy  wax." 
May  be  kneaded  like  wax.  Softens  in  heat  of  hand.  Feels  greasy.  Melts  readily  like  sealing-wax,  but 
will  not  adhere  to  paper  unless  very  hot.  Takes  impression  of  the  seal.  Electrically  excited  by  friction. 
Under  high  heat  the  interior  may  be  drawn  into  threads.  Wurtzilite  is  a  jetlike  variety  which  is  sectile, 
somewhat  like  gutta-percha,  and  slightly  elastic,  but  brittle  when  cold;  more  elastic  if  quietly  warmed. 
Fuses  readily,  but  resists  the  ordinary  solvents  of  bitumen.  When  warmed  becomes  more  plastic. 

Occurs  with  former  and  related  materials  in  Utah,  etc.,  and.  like 
the  former,  has  probably  some  connection  with  the  asphalt  de- 
posits there.  It  is  also  found  in  Europe  with  coal  or  bituminous 
deposits;  also  associated  with  petroleum  in  sandstone  in  Galicia, 
Saxony,  etc. 


76 


CHARACTERS. 

TREATMENT  WITH  ACIDS,  ETC. 


action    with    HC1    or 
HN03. 


Soluble  in  petroleum 
or  warm  oil  of  turpen- 
tine. Ether  slowly 
dissolves  powder. 


Soluble  in  boiling  ether 
or  benzene.  The  di- 
lute solution  is  highly 
fluorescent. 


Tninu                  I  II<;TRR          STRFAK-         Fusi-          HARD- 
BILITY.             NESS. 

1                               1                       1                       I                        1 

SP.  GR. 
1.4 

1.  06 

CRYS- 
TALLI- 
ZATION 

Amor- 
phous 

Amor- 
phous 

MAGNETIC 

BEFORE 
OR  AFTER 

HEATING 

USES. 

Pitch-  or 
jet-black. 

Black. 

White  to 
yellowish 
brown  and 
darker 
shades. 

Lus- 
trous, 
bril- 
liant. 

Lus- 
trous. 

Dull, 
trans- 
lucent. 

Black 

Rich 
brown 

Like 
color. 

Imper- 
fect. 

Easily 

Melts 
at 
6i°C. 

2 
2.25 

There  is  a  limited  demand 
for  this  mineral  as  well  as 
the  two  former  among  the 
manufacturers  of  certain 
grades  of  carriage-varnish 
and  stove-blacking. 

Largely  used,  especially  in 
Russia,  as  a  substitute  for 
beeswax.  The  mineral  is 
distilled,  and  the  resulting 
wax  is  employed  in  the 
manufacture  of  candles. 

Soft. 

0.85- 
0.95 

Amor- 
phous 

which  are  especially  adapted  for  use  in  high  latitudes. 
Refined  ozokerite  is  used  in  the  manufacture  of  waxed 
paper,  for  the  lining   of    wooden  vessels,  in   the  manu- 
facture of  varnish  and  blacking,  for  adulterating  bees- 
wax, for  calking  ships,  for  making  liniments,  plasters, 
salves,  shoemakers'  wax,  wax  ornaments,  toy  figures,  in 
the   manufacture   of   heavy   lubricants    where    body   is 
requisite,  and  for  any  of  the   thousand  or  more  uses  to 
which  beeswax  is  applicable. 

77 


NAME. 


COMP.  ANf> 

PERCENTAGE 
OF  IMPORTANT 
CONSTITUENT. 


GENERAL  CHARACTERS  AND  ASSOCIATIONS. 


BEFORE  BLOWPIPE. 


HYDROCARBONS. 

Mixture  of 
different 
hydro- 
carbons, 


liquid. 
Asphalt. 


part  of 
which  are 
oxy- 
genated. 


-Continued. 

Seems  to  be  the  residue  after  the  distillation  of  the  lighter  and  more  volatile  oils,  being  variable  in  com- 
position. Fusible  and  inflammable,  and  burns  with  bright  flame.  Is  more  or  less  soft,  has  a  bituminous 
odor,  often  melts  in  heat  of  sun  (at  90°  to  100°),  and  flows  like  wax,  then  becomes  hard  on  cooling. 
It  varies  from  tough  and  somewhat  hard  material  to  soft  and  viscid  substances,  according  to  composi- 
tion and  different  physical  characteristics.  It  grades  insensibly  from  the  solid  bitumen  into  the  viscid 
bitumen,  maltha,  or  mineral  tar  (pitt  asphalts),  through  which  there  is  a  gradation  to  petroleum.  The 
thin  varieties  usually  bespeak  the  presence  of  the  "lighter  oils,"  which  detract  from  its  value  as  a 
paving  material.  These  lighter  oils(vaporizable  at  about  110°  orbelow)are  usually,  however,  sparingly 
present,  while  the  heavy  oils  (vaporizable  at  from  100°  to  250°)  constitute  sometimes  as  much  as  &$%  of 
the  mass. 

Principal  deposit  is  the  famous  pitch  lake  of  Trinidad.  There  are  similar  deposits  in  Venezuela  on  the 
mainland.  It  is,  however,  widely  distributed  throughout  the  United  States,  either  in  beds  or  as 
impregnating  sandstones,  shales,  and  limestones,  in  Kentucky,  Indian  Territory,  Texas,  Utah,  etc., 
largely  admixed  with  extraneous  material.  Occurs  in  many  places  in  Europe,  but  the  better  variety 
seems  to  be  associated  with  limestone,  as  at  Val  de  Travers.  It  is  a  very  generally  distributed 
mineral,  and  is  found  in  many  parts  of  the  world.  It  occurs  in  many  localities  where  petroleum  is  found. 


c.             Principally  "  Mineral  oil."      Density  .6  to   .85.      Of  many  colors,  but  usually  dark  greenish  brown.      Disagreeable 

Liquid.          composed  odor.     Varies  also  in  consistency  from  the  thin  flowing  kind  into  those  which  are  thick  and  viscous,  and 

of  mem-  thence  by  insensible  gradation  into  the  solid  bitumen  or  asphalt. 

Petro-  bers  of  the  Occurs  most  abundantly  in  certain  sandstone  strata  underlying  the  coal  measures,  as  in  Pennsylvania, 
leum.  paraffin  West  Virginia,  etc.  It  is  also  found  in  limestone  in  Ohio,  where  this  rock  furnishes  most  of  the  pro- 
series,  duction  afforded  by  that  region.  It  is  not,  however,  confined  to  the  older  strata,  but  is  frequently  found 
with  a  in  Tertiary  strata,  as  in  Russia.  The  exact  origin  of  petroleum  and  the  other  hydrocarbons  is  unknown, 
smaller  but  they  are  presumed  to  have  had  their  origin  in  organic  matter  (vegetable  or  animal,  or  both)  which 
percent-  accumulated  in  the  sedimentary  material  in  which  these  deposits  are  found.  It  is  found  in  sedimentary 
age  of  strata  of  all  ages,  from  Silurian  up  to  Tertiary,  in  the  United  States  more  particularly  in  Silurian, 
olefines.  Devonian,  and  Subcarboniferous  formations.  Owing  to  the  nature  of  its  origin,  it  is  not  found  in 
Variable.  association  with  eruptive  rocks. 

78 


CHARACTERS. 

£               MAGNETIC 



COLOR.               LUSTRE. 

STREAK        Fusi'         HARD-        s     G           TALLI"-          BEFORE                                     ., 

FREAK         BJLITY.             NESS.             SP>  '        '          TALLI             OR  AFTER                                                        SES> 

TREATMENT  WITH  ACIDS,ETC. 

°          HEATING. 

|                   1                 1                  I                 1                  1                      .1 

In    closed   tube    gives 

Usually              Dull 

Like        Melts      Varia-      i-r.8      Amor-                        By  far  the  greatest  consump- 

empyreumatic      oil, 

black  to              like 

color.      at  90°      ble.                        phous                           tion  of   this    mineral   is  for 

some  ammoniacal  wa- 

brownish          black 

to                                                                                street-paving,  but  it  is  also 

ter,  combustible  gases, 

black.                 pitch. 

100°                                                                                used  as  a  covering  for  many 

and    leaves    carbona- 

C.                                                                                   kinds  of  wooden,  iron,  and 

ceous  residue.      Does 

other  constructions,  so  as  to 

not  color  potash  solu- 

protect them  from  decay  or 

tion.     Powder   boiled 

rust.      Used    for   preparing 

with  ether  imparts  to 

roofiner-felts  and  for  water- 

it a  wine-   or  brown- 

proof  material  for  coating  water-pipes,  in  me- 

red     color.       Soluble 

chanical  engineering    for   the  foundations  of 

mostly   in    ether   and 

dynamos,    steam-hammers,    and    other    ma- 

oil of  turpentine, 

chinery   where  jarring  is  to  be  suppressed. 

partly  in  alcohol,  but 

It  is    employed   in    various    forms  in   naval, 

some     solid    asphalts 

military,     sanitary,    electrical     and     mining 

are  not  at  all  soluble 

constructions.     It  is  also   employed    in   var- 

in the  latter. 

I  ,      , 

nishes,  photography,  and  otherwise. 

Soluble  in  benzene  or 

Dark  yellow 

0.6- 

Petroleum  and  its  products, 

camphene. 

to  brown, 

0.9 

besides  being  used  as  an  il- 

and  nearly 

luminant,  and  as  a  source  of 

black  and 

power   and    great     heat    in 

greenish 

metallurgical    processes,    is 

brown. 

employed   for  a  vast  number  of  other  purposes.     It  is  used  in  the  pro- 

duction of  gas,  as  an  enricher  of  common  coal-gas,  and  when  refined  the 

waste  products  are  employed  in  the  manufacture  of  the  various  kinds  of 

aniline  dyes,  in  the  manufacture   of  paraffin  candles,  and  in  the  manu- 

facture of  many  salves,  etc.,  used  in  medicine.     Crude  petroleum,  as 

well  as  some  of  the  refined  products,  is  largely  used  as  a  lubricant. 

NAME. 


COMP.  AND 
PKRCBNTAGK 
OF  IMPORTANT 
CONSTITUENT. 


SPECIFIC 


GENERAL  CHARACTERS  AND  ASSOCIATIONS. 


BEFORE  BLOWPIPE. 


HYDROCARBONS  —Continued. 


d. 

Gaseous. 
Natural 
Gas. 


CH4.  Volatile,  inflammable,  etc. 

Variable.  Occurs  in  the  same  regions  and  under  much  the  same  conditions 
as  petroleum.  Being  volatile,  when  in  connection  with  oil, 
it  is  usually  found  above  the  oil.  It  is  frequently  found,  how- 
ever, in  oil  regions  where  the  well  yields  nothing  but  gas. 


Infuso- 
rial 
Earth 
(Tripo- 
lite). 


Essen-  Earthy  or  sometimes  chalk-like  material,  largely  or  entirely  made  up  of  silicious  skeletons  of  diatoms  or 

dally  with  fine  spicules  of  sponges.     Feels  harsh   between   the  fingers,  and  glass  is  scratched  when  rubbed 

SiO2.  becomes  opaque.     Some  yellow  varieties  containing  iron  oxide  turn  red.     Soluble  in  hydrofluoric  acid 

Some-  than  quartz;  also  soluble  in  caustic  alkalies,  but  more  readily  in  some  varieties  than  in  others, 

times  Occurs  in  quite  thick  stratified  deposits,  sometimes  beneath  peat- 

contains  beds,  and  is  obtained  for  commerce  in  the  following  States :  Maine, 

a  small  New  Hampshire,  Massachusetts,  Virginia,  California,  Nevada, 

amount  Missouri,  etc.     It  is  also   found  in  many  other  portions  of  the 

of  water.  world,  as  in  Barbadoes,   Bohemia,  Sicily,  Calabria,  Greece,  the 

Nicobar  Islands,  and  Nova  Scotia.  In  nearly  all  of  these  locali- 
ties the  beds  are  of  Tertiary  age.  In  some  regions  it  is  hard 
and  indurated  through  consolidation  due  to  infiltrating  waters. 
It  thus  graduates  into  chert  and  opal. 


80 


CHARACTERS. 

TREATMENT  WITH  ACIDS,  ETC. 


COLOR. 


LUSTRE.       STREAK      £<£; 


CRYS- 


MAGNETIC 

BEFORE 
OR  AFTER 

HEATING. 


microscopic  plants, 
with  it.  Infusible,  but 
somewhat  more  readily 


White  or 
grayish, 
earthy  or 
chalky,  but 
often  col- 
ored by 
various 
impurities. 


Earthy. 


Whit- 
ish or 
like 
color. 


Infus.     5.5-6.5     1.9-2.3 


Amor- 
phous 


81 


USES. 


Besides  being  used  in  its 
natural  condition  for  light- 
ing, it  has  been  extensively 
employed  in  the  regions 
where  it  is  found  for  heating 
and  cooking  in  residences, 
and  for  a  time  to  a  large  ex- 
tent it  was  used  in  the  place 
of  coke  in  the  manufacture 
and  treatment  of  iron,  and 
in  many  manufacturing  and 
industrial  establishments. 

This  is  used  and  sold  in  com- 
merce as  a  polishing  pow- 
der under  the  names  "  elec- 
tro-silicon" and  "  silex."  It 
is  also  used  for  making 
solutions  of  soluble  silica 
(soda  silicate),  and  for  pur- 
poses of  a  cement.  Owing 
to  its  poor  conduction  of 
heat,  it  has  been  applied  as 
a  protection  to  steam  boilers 
and  pipes.  It  is  sometimes 
used  to  give  body  to  soap. 


COM  P.  AND 

NAME. 

PERCENTAGE 
OF  IMPORTANT 

CONSTITUENT. 

Iridium. 

Iridium  and 

Osmium 

(Iridos- 

in  differ- 

mine.) 

ent  pro- 

portions, 

in  which 

the  irid- 

ium  varies 

from 

40%  to  10%. 

GENERAL  CHARACTERS  AND  ASSOCIATIONS. 


Generally  in  combination  with  osmium  or  platinum  or  allied 
metals.  Harder  than  platinum.  Usually  in  foliae  or  irregular 
flattened  grains.  Slightly  malleable  to  nearly  brittle.  Hard- 
ness varies  in  proportion  to  amount  of  the  other  softer  metals 
with  which  it  is  always  alloyed. 

Usually  found  in  alluvial  or  gravel  deposits  (placers)  with  grains 
of  platinum,  gold,  chromic  iron  ore,  etc.  Small  quantities  are 
found  in  Oregon  and  elsewhere  on  the  Pacific  Coast. 


SPECIFIC 


BEFORE  BLOWPIPE. 


Wholly  unaltered  B.  B.  or  by  fluxes. 


IRON  AND  ITS  COMPOUNDS. 

With  borax  in  O.  F.  oxide  of  iron  gives  a  dark  brown-red  glass,  which  becomes  pale-yellowish  or  colorless  on  cooling;  in 
become  magnetic  when  heated  with  soda  on  charcoal,  and  dissolve  readily  in  HC1;  sulphide  of  ammonium  gives  to  their  solution  a 
excellent  test  is  to  add  ferrocyanide  of  potassium  to  solution.  A  pale-blue  precipitate  indicates  ferrous  salts,  and  a  dark  blue 
borax  orsalt  of  phosphorus  bead  becomes  violet-blue  or  reddish  purple  when  the  R.  F.  is  directed  upon  it,  especially  if  tin  be  added, 
to  boil.  Set  aside.  If  titanium  is  present,  the  solution  becomes  violet  in  color.  The  presence  of  chromium  is  also  readily 


CHARACTERS. 

MAGNETIC 



COLOR. 

LUSTRE. 

STREAK 

FUSI- 
BILITY. 

HARD- 
MESS. 

SP.  GR. 

CRYS- 
TALLI- 

BEFORE                                                    n 
OK  AFTER 

TREATMENT  WITH  ACIDS,ETC. 

ZATION. 

HEATING 

Not  attacked  by  acids, 

Pale  steel- 

Metal- 

Like 

Infus. 

6-7 

19-21 

III. 

Owing   to    its   hardness,   its 

except      slightly      by 

gray  to  tin- 

lic. 

color. 

principal     use     is     for    the 

heated  aqua  regia. 

white  to 

points  which   are  affixed  to 

lead-gray. 

the   nibs   of  gold  pens,  and 

for  the   knife-edges  of   fine 

balances,    for    the    tips     of 

rubber-turning  tools,  for  wire 

draw-plates,  etc.     An  alloy 

of    pure    iridium    and    pure 

» 

platinum    has  been   adopted 

for  the  standards  of  weights 

and    measures,   on    account 

of    its    indestructibility   and 

other    desirable    attributes. 

In  the  condition  of    sponge 

and  oxide  it  is  used  in  pho- 

tography and  the  ceramic  art 

for   obtaining    a    dense   black,    also    by 

jewellers    for    obtaining    black    under 

. 

white   enamel.      In   all   such   cases   its 

- 

use  is  due  to  its  infusibility. 

R.  F.  bottle-green   on  cooling.     With  tin   the  green   color  is  hastened      Most  of  the   compounds     This   metal    is    put   to   more 
black  precipitate,  which  is  soluble  in  dilute  HC1,  distinguishing  it  from  cobalt  and  nickel.     Another       manifold    and    more    useful 
precipitate,  ferric  salts  of  iron.     The   presence  of  titanium  maybe  detected  by  the  fact  that  the 
and  test  made  on  charcoal.     A  better  test  is  to  add  tin  to  concentrated  HC1  solution,  and  continue 
detected.     (See  Chromic  Iron.) 


83 


purposes  than  any  other 
known  to  man.  It  is  not 
considered  necessary  to  at- 
tempt to  enumerate  them. 


NAME. 


COM  p.  AND 
PERCENTAGE 
OF  IMPORTANT 
CONSTITUENT. 


GENERAL  CHARACTERS  AND  ASSOCIATIONS. 


IRON  AND  ITS  COMPOUNDS.— Continued. 

Mag-  FesO4.  Easily  recognized    by  streak   and   strong  magnetism,  which    dis- 

netite  tinguish  it  from  the  following.     Very  common,  hard,  compact, 

(Mag-          Iron,  and  massive  ore. 

netic  72.39*.     Occurs  principally  in  metamorphic   rocks  and  as  grains  scattered 

Iron  through  eruptive  rocks.     In  great  beds  in  the  earlier  stratified 

Ore).  formations  which  are  now  often  metamorphosed   into    granite, 

gneiss,  and  the  various  schists.  Sometimes  found  in  connection 
with  the  older  limestones.  In  the  western  United  States  it  fre- 
quently marks  the  outcroppings  of  fissure-veins  or  contact-de- 
posits, and  in  such  cases  it  is  usually  superficial  and  owes  its 
origin  to  the  oxidation  of  iron  pyrites  contained  in  the  vein. 

Hematite     FeaO3.  Scaly,  fibrous,  and  compact,  columnar.     Sometimes  concretionary, 

Varieties  reniform,  or  botryoidal  (kidney  ore).     Red  powder,  and  the  mag- 

are  :  Iron,     70^.         netism  so  easily  induced  in  it  by  R.  F. ,  serve  to  distinguish  it. 

Occurrence  much  the  same  as  above.  Often  in  great  interbedded 
masses  in  the  older  crystalline  or  metamorphic  rocks  especially, 
but  is  found  in  rocks  of  all  ages.  Like  magnetite,  it  often  in 
the  western  part  of  the  United  States  marks  the  outcrop  or 
oxidized  portion  of  fissure-veins,  contact-deposits,  isolated 
pockets  in  limestone,  etc.,  which  contain  at  greater  depths 
large  quantities  of  pyrites.  Often  intimately  associated  with 
magnetite,  as  in  Michigan,  etc. 


SPECIFIC 


BEFORE  BLOWPIPE. 


Magnetic  before  heating,  usually 
strongly,  but  sometimes  only  feebly; 
sometimes  having  polarity.  Reacts 
for  iron.  Generally  fusible  above 
5.  In  O.  F.  loses  its  influence  upon 
the  magnet. 


Heated  in  R.  F.  readily  becomes  mag- 
netic, and  if  treated  with  soda  on 
charcoal  is  reduced  to  a  gray  mag- 
netic metallic  powder. 


CHARACTERS. 


COLOR. 


TREATMENT  WITH  ACIDS,  ETC. 


LUSTRE.       STKKAK 


SP.  GR.  TALLI- 


CRYS-       MACMmc 


J 


USES. 


Reacts  for  iron. 


Reacts  for  iron. 


Iron-black.       Splen- 
dent, 
metal- 

Black 

5 

5-5- 
6.5 

5-17 

I. 

Both.         See  under  heading  IRON,  etc. 

lic  to 

subme- 

1 

tallic 

• 

and 

dull. 

• 

Dark  steel-       When 
gray,  iron-      crystal- 
black  to            lized, 
brown-red        splen- 
and  reddish     dent, 
varieties.          Usually 
metallic 
to  sub- 

Cher- 
ry-red 
to 
brown- 
ish-red. 

Infus. 
or 
above 
5- 

5-5- 
6-5 

4.2- 
5-2 

III. 

After.  When  pulverized  it  is  some- 
times used  for  polishing 
metal.  When  in  an  earthy 
condition  it  is  used  in  the 
manufacture  of  crayons,  for 
polishing  glass,  and  as  a 
red  paint. 

metallic. 
Some- 

- 

times 

dull. 

- 

fi 

K 

NAME. 


COMP.  AND 

PERCENTAGE 
OF  IMPORTANT 

CONSTITUENT. 


GENERAL  CHARACTERS  AND  ASSOCIATIONS. 


SPECIFIC 


BEFORE   BLOWPIPE. 


IKON  AND  ITS  COMPOUNDS. -Continued. 

(a)  Fe2O3.  Hard,   compact,    and"  crystalline.      Massive.       That    from    Lake 

Specular.  Superior  region   generally   spoken  of   in  commercial   language 

Iron,     70%.         as  hard  specular,  or  hard  red  specular. 

In   interbedded    masses  in  crystalline   rocks,  as  in  Michigan,  etc. 
A  valuable  ore. 


Same  as  above. 


(6)           FeaOs.  These  varieties  possess  a  foliated,  scaly,  or  micaceous  structure.     This  specular  schist  often  resembles 

Mica-  called  itabiryte.     Reacts  as  above  B.  B.  and  with  acids.     Variety  of  the  preceding.     Some  kinds  are  soft 

ceous.         Iron,     7ug.  Like  the  above  ores  occurs  in  crystalline  and  usually  schistose  rocks.     Michigan,  etc. 

(c)           Fe2O3.  Hematite  in  octahedrons,  derived,  it  is  supposed,  from  oxidation  of  magnetite,  with  which  it  is  commonly 

Martite.  guished  by   its   purple   streak.         N.B. — Sometimes  ore  is  found  giving   red   streak,    yet   possessing 

Iron,     yojt.  to  presence  of  magnetite  in  the  mass.     Michigan,  etc. 


(rf)          Fe203 
Soft 

Hema-        Iron, 
tite. 


A  soft,  earthy  variety,  but  often  very  pure.     Loose  and  uncompact  to  semi-consolidated.     Often  man- 
ganiferous.     (Abundant  and  valuable  ore.     Michigan.)    Sub-variety  bluish. 


86 


. 

CHARACTERS 

f     -        MAGNETIC 

COLOR.              LUSTRE.        STREAK 

Fusi-         HARD-      cp    Cv        ,T*ITT"          BEFORE                                   TT 

BILITY.             NESS.                                        _._.__"          OR  AFTER 

TREATMENT  WITH  ACIDS,  ETC. 

II1UN-       HEATING. 

Same  as  above.                   Dark  steel-       Perfect-      Red 

Infus.       5.5-           5            III.       After.         See  under  heading  IRON,  etc. 

gray  to  red-      ly  me-        or  red- 

or            6.5 

dish-black,        tallic.         dish- 

above 

reddish,             Often        brown 

5- 

iron-black.        splen- 

;        dent. 

-_(_.  __  L 

mica  schist,  when  it  is     Light  to             Splen-        Red- 

Infus.        5.5-           5            III.       After.         See  under  heading  IRON.  etc. 

and  unctuous.                       dark  steel-        dent            dish. 

or             6.5 

gray. 

metal- 

above 

lic. 

* 

associated.      D  is  tin-     Iron-bl 

ick        Sub-            Pur- 

Infus.        6-7            5              I. 

After.         See  under  heading  IRON,  etc. 

magnetism,  always  due      to  reddish         metal-       plish 

or 

Some- 

black or            lie.              or 

above 

times 

bronze 

tar-                         red- 

5- 

feebly 

nish. 

dish 

before. 

brown 

. 
,  ,.  .  „  ..  L,  ,   .  , 

-        ' 

Dull  red,           Earthy.      Pur- 
reddish  to                          Plish 

Infus.     Varia-       4-5       Amor-    After.         See  under  heading  IRON,  etc. 
or             ble.                        phous 

yellowish                           ™?' 

above 

brown, 

reddish 

5- 

8 

NAME. 


COMP.  AND 
PERCENTAGE 
OF  IMPORTANT 
CONSTITUENT. 


GENERAL  CHARACTERS  AND  ASSOCIATIONS. 


SPECIFIC 


BEFORE  BLOWPIPE. 


IRON  AND  ITS  COMPOUNDS.— Continued. 


Fossil  Ore 
(Lenticu- 
lar iron 
ore),  etc. 


Red 
Shale 
Ore. 


Red 
Ochre. 

Turgite. 


FeaO,. 
Iron,     70*. 


Fe,  Os. 
Iron,     70%. 


Fe2O3. 
Iron, 


Iron, 


66.2*. 


Commonly  called  fossiliferous  red  hematite.  Oolitic  or  composed  of  aggregations  of  small,  flattened, 
different  sizes.  Usually  contains  a  large  percentage  of  impurities  (lime,  clay,  sand,  etc.).  Often  includes 
fossil  remains.  This  variety  is  both  hematite  and  limonite  in  character,  but  more  frequently  the 
latter  description  it  affords  the  characteristic  yellowish  powder.  Another  variety  is  argillaceous 
stone,  which  is  hard,  brownish  black  to  reddish  brown  or  dull  red,  submetallic  to  unmetallic  and  has  a  red 
is  thus  easily  distinguished  from  the  clay  iron-stones  of  the  species  brown  clay  iron-stone  (limonite) 
stone  (siderite). 


Often  an  admixture  of  hematite  and  limonite. 
impure. 


Compact,  looking  much  like  compact  red  shale.    (Virginia, 


Earthy  or  pulverulent   form  (used   for  pigments), 
mixed  with  more  or  less  clay. 


Soft  and  earthy.     Often  associated  with  the  above. 


Often  associated  with  limonite,  for  which  it  is  frequently  mis- 
taken, but  it  is  harder,  has  a  different  streak,  and  decrepitates  in 
closed  tube.  Often  constitutes  aji  exterior  layer  of  limonite. 
When  botryoidal  has  much  the  same  smooth  lustrous  surface. 
Supposed  to  be  intermediate  stage  in  alteration  of  limonite  to 
hematite.  Another  intermediate  variety  less  common  than  this 
is  goethite,  containing  62.9^  of  iron  and  10.  i%  of  water.  Found 
with  both  hematite  and  limonite.  Liver-brown  color,  reddish 
streak  like  limonite.  The  so-called  velvet  ore  is  frequently  of 
this  variety. 

Occurs  with  other  ores  of  iron,  especially  in  the  older  beds,  and  in 
intimate  association  with  limonite. 


Heated  in  closed  tube  flies  to  pieces 
and  yields  water. 


I 

CHARACTERS. 
TREATMENT  WITH  ACIDS,  ETC 

COLOR. 

LUSTRE. 

STREAK 

FUSI- 
BILITY. 

HARD- 
NESS. 

CRYS- 
SP.  GR.       TALLI- 

ZATION. 

MAGNETIC 
BEFORE                                  _T 
OR  AFTER                                 USES. 
HEATING. 

concretionary  grains  of     Reddish  to        Dull.           Red-       Infus.      4.5-6           5           III(?) 
fossils  or  composed  of      brownish.                            dish         or 

After.         See  under  heading  IRON,  etc. 

former.     When  of  the                                                    brown      above 

hematite    or    clay    iron-                                                        to               5. 

streak.      This    species 

pur- 

and ordinary  clay  iron- 

plish 
red. 

.. 

etc.)      Generally   very     Reddish  to        Earthy       Red-         Infus.      4.5-6           5           IH(?) 
brownish.          and            dish  to       or 

After.         See  under  heading  IRON,  etc. 

dull.          |>srhown-      above 

r 

5- 

Usually  impure,  being     Earthy  red. 

Often  used  as  paint. 

Like  hematite,.                   Reddish            Subme-       Red.           5            5-6         4.14       Amor- 
black,  dark       tallic,                                                                       phous 

After.         See  under  heading  IRON,  etc. 

red  to                 satin- 

bright  red.        like, 

duil, 

earthy. 

; 

' 

8 

) 

NAME. 


COMP.  AND 

PERCENTAGE 
OF  IMPORTANT 
CONSTITUENT. 


GENERAL  CHARACTERS  AND  ASSOCIATIONS. 


SPECIFIC 


BEFORE  BLOWPIPE. 


IRON  AND  ITS  COMPOUNDS.— Continued. 


Limonite 
(Brown 
Hema- 
tite). 
Varie- 
ties are: 


Bog 
Iron 
Ore. 


Yellow 
Ochre. 


2Fe2Os. 
3H20. 

Iron,  59.! 


2Fe2Os. 
3H20. 

Iron,  59 


2Fe»Oa. 


Iron,  59-8*. 


Compact,  often  dense  when  pure.  Botryoidal,  stalactitic  with 
compact  fibrous  structure  within,  but  also  massive,  etc.  Not 
crystalline.  Tendency  to  form  acicular,  sometimes  stalactitic 
concretionary  masses,  with  long  needle-like  fibres  radiating  from 
common  centre;  but  generally  amorphous.  Common  ore. 

Occurs  in  rocks  of  all  ages.  It  has  resulted,  it  is  supposed,  from 
the  decomposition  of  other  iron-bearing  rocks  or  minerals. 
This  is  shown  by  the  stalactitic  and  other  forms  in  which  it 
occurs.  Like  hematite  and  magnetite  it  frequently  marks  the 
outcroppings  of  fissure-veins,  having  been  produced  by  the 
decomposition  of  the  original  pyrites  or  siderite  in  the  vein. 

Simply  a  vesicular  and  generally  impure  variety  of  the  above. 
Recognized  by  its  comparatively  light  weight,  yellow  color,  and 
loose  or  porous  texture.  Often  petrifying  wood,  leaves,  etc. 

Usually  superficial,  and  occurs  in  swampy  places  containing  vege- 
tation—  often  decomposing  —  into  which  places  have  flowed 
waters  containing  iron  in  solution,  the  iron  having  been  precipi- 
tated by  the  presence  of  the  organic  matter. 

Earthy  or  pulverulent  form  of  above.    Earthy,  brownish,  yellow  to  ochre-yellow, 
mixed  with  more  or  less  clay,  sand,  etc. 


With  difficulty  fusible  to  a  magnetic 
mass.  Some  varieties  leave  a  sili- 
cious  skeleton  on  salt  of  phos- 
phorus bead. 


Gives  all  the  reactions  of  the  above. 


Usually  impure,  being 


90 


CHARACTERS. 

TREATMENT  WITH  ACIDS,  ETC. 


COLOR. 


LUSTRE.       STREAK 


FUSI- 
BILITY. 


HARD- 
NESS. 


SP.  GR. 


CRYS- 
TALLI- 
ZATION. 


MAGNETIC 
BEFORE 

OR  AFTER 

HEATING. 


USES. 


Reacts  for  iron.  Yields 

Brown, 

Dull, 

Brown- 

5 

5-5-5 

3*6-4 

Amor- 

After. 

Limonite   is   also   used,    like 

much  water  (of  which 

various 

earthy 

yellow 

phous 

hematite,  for  polishing  me- 

it contains    14.555  and 

shades, 

to  sub- 

to 

tallic     buttons      and     other 

often  more)  in  closed 

yellow, 

metal- 

yellow. 

articles.     When  earthy  it  is 

tube.        Soluble,     but 

black. 

lic. 

a     common     material      for 

with  difficulty,  in  HC1. 

Never 

Some- 

paint. 

leaving    frequently  a 

bright. 

times 

silicious  residue. 

silky. 

- 

As  above. 

Yellowish  to 
brownish. 

Dull. 

Brown- 
yellow 
to 

5 

4-4-5 

'—"  -  -    -  - 

Varia- 
ble. 

Amor- 
phous 

After. 

See  under  heading  IRON,  etc. 

- 

• 

yellow. 

» 

like     "  Red      Ochre," 

After. 

Used  as  a  paint  or  in  paint- 
mixtures. 

9 

r~ 

NAME. 


CoMP.  AND 

PERCENTAGE 
OF  IMPORTANT 
CONSTITUENT. 


GENERAL  CHARACTERS  AND  ASSOCIATIONS. 


SPECIFIC 


BEFORE  BLOWPIPE. 


IRON  AND  ITS  COMPOUNDS.— Continued. 
FeCOs. 


Siderite 
(Spathic 
Iron 
Ore)  or 
Iron 
Carbon- 
ate. 

Varieties 
are: 

Clay 
Iron- 
stone, 


Black 
Band 
Ore. 
Subva- 
riety  of 
above. 


Iron,  48.2^. 


FeCO3. 

Same,  but 
very  va- 
riable, ac- 
cording to 
impuri- 
ties. 


Same,  but 
very  va- 
riable, ac- 
cording to 
impuri- 
ties. 


Becomes  magnetic  upon  heating  R.  F. 
With  borax,  gives  reaction  for 
iron.  Decrepitates  in  closed  tube 
and  gives  off  CO2  blackens  and 
becomes  magnetic. 


Often  crystalline.     Worked  extensively  in  Europe. 

Occurs   in   many  series  of  stratified  rocks  from  the  oldest  to  the 

youngest.     Frequently  found  as  stratified  deposits  in  connection 

with  coal  formations,  but  it  is  also  found  in  large  irregular  de- 

posits  in  limestone.     Less  frequently  it  is  found  forming  part  of 

the  frilling  of  fissure-veins,  when  it  is  usually  crystallized  and 

associated   with    the   metallic  ores.      In   the    former   cases   its 

occurrence  is  usually  massive,  and  as  such  it  is  an  important  ore 

of  iron.     Ankerite,  crystallized  dolomitic  variety. 

Name  commonly  given  to  compact,  earthy,  or  stony  kinds  of  above,  which  are  rendered  impure  by  an 
sand.  In  many  formations,  especially  among  the  coal  measures  (England,  etc.).  Fracture  finely  granular. 
gives  out  an  argillaceous  odor  when  breathed  upon.  Sometimes  as  flattened  spheroidal  concretionary 
or  oolitic;  also  granular  to  massive.  Sometimes,  when  reddish  in  color,  consists  of  impure  hematite, 
of  impure  limonite;  when  unoxidized,  however,  is  simply  a  more  or  less  impure  iron  carbonate. 

This  variety  of  the  above  occurs  in  rocks  of  all  ages,  the  specular 
variety  (argillaceous  hematite,  see  fossil  ore)  being  mostly 
confined  to  the  older  rocks.  Also  described  as  being  the  result 
of  igneous  action  about  some  volcanoes,  as  at  Vesuvius.  (Dana.) 

A  common  variety  of  above,  occurring  in  coal  measures,  and  containing  sometimes  as  much  as  25^  to  30*  of 
A  valuable  ore  in  England,  where  the  ore  sometimes  contains  enough  carbonaceous  matter  to  effect  the 
lie  state  without  addition  of  anything  except  limestone. 


CHARACTERS. 

CRYS-       MAGNETIC 
COLOR.              LUSTRE.       STREAK      £™^        ^ARC-       Sp  GR        T^       O*EAF°**R                                 USES. 

TREATMENT  WITH  ACIDS,  ETC. 

—  

Soluble  in  heated  HC1, 

Ash,  yellow-     Vitre-         White 

4-5         3-5~4         3-8          HI.       After.         See  under  heading  IRON,  etc. 

with      effervescence 

ish  and              ous,  in-     or 

(CO3),    which    is    also 

brownish           clining      uncol- 

given     off    when    the 

gray  to               to 

ored 

ore  is  heated  inclosed 

brown-red.        pearly,      ex- 

tube. 

Sometimes 

cept 

green  and 

by  im- 

white. 

puri- 

1  ties. 

M  ?. 

admixture    of   clay  or 

Yellowish          Dull.           Whit- 

4-5 

3-7 

3.4        Amor-     After.         See  under  heading  IRON,  etc. 

Easily    scratched,   and 

brown  to 

ish  or 

phous 

massesof  various  sizes, 

reddish 

gray- 

s 

or,  if  brown  or  yellow, 

gray. 

ish. 

• 

carbonaceous     matter. 

Amor-    After.         See  under  heading  IRON,  etc. 

Grayish             Earthy,      Dark 

1 

3-5 

3 

reduction  to  the  metal- 

black.                 dull.            gray, 

phous 

etc. 

NAME 


COMP.  AND 
PERCENTAGE 
OF  IMPORTANT 
CONSTITUENT. 


GENERAL  CHARACTERS  AND  ASSOCIATIONS. 


IRON  AND  ITS  COMPOUNDS.— Continued. 

Titanic 
Iron  Ore 
(Ilmen- 
ite  or 
Menac- 
canite). 


SPECIFIC 


BEFORE  BLOWPIPE. 


Chromic 
Iron. 


(TiFe)2O3.  A  hematite  in  which  part  of  the  iron  is  replaced  by  titanium.    The 

Variable.  presence  of  titanium  is  highly  prejudicial  to  the   value  of  any 
iron   ore    and,   unless    the    quantity  is  very   minute,  renders  it 

If  normal,  worthless  as  an  ore  of  iron. 

Titanium,  Occurs  in  massive  beds  in  gneiss  and  other  crystalline  rocks,  also 

31. 6#.  disseminated  through  these  rocks  and  as  iron-sands  (iserine). 

Iron,  36. 8#.  Frequently  associated  with  magnetite. 

(Chrom-  See  Chromium  and  its  Compounds, 
ite.) 


Feebly  magnetic.  To  borax  or  salt 
of  phosphorus  bead  imparts  an  in- 
tense brown-red  color  in  R.  F., 
which,  if  tin  be  added,  changes  to 
violet  red. 


FeS2 


Iron 
Pyrites. 

Varieties:     Iron,  46. 6#. 
Sulphur, 

53-4*- 


Marcasite 
(Cocks- 
comb 
'Pyrites); 
(White 
Iron 
Pyrites). 


FeS2. 

Iron,  46.6%. 
Sulphur, 
53.4*. 


Common  pyrites.  Distinguished  from  copper  pyrites  by  its  su- 
perior hardness  and  paler  color.  Cubes  with  striated  surfaces, 
striae  at  right  angles  to  one  another.  Brittle  with  conchoidal 
uneven  fracture.  Common  source  of  sulphuric  acid  and  often 
auriferous. 

Occurs  abundantly  in  rocks  of  all  ages,  frequently  disseminated 
through  them,  from  the  oldest  crystalline  rocks  to  the  most 
recent  alluvial  deposits.  A  very  common  mineral  in  fissure- 
veins  and  contact-deposits.  It  is  yery  frequently  associated  with 
such  minerals  as  quartz,  galena,  blende,  copper  pyrites,  etc.,  etc. 

Same  as  above,  but  of  different  crystalline  form.  Sometimes 
called  capillary  pyrites,  but  this  term  properly  applies  to  sul- 
phide of  nickel  (millerite). 

Associations  the  same  as  above. 


Gives  only  reaction  for  iron.  Gives 
off  sulphur  B.  B.  on  charcoal,  burn- 
ing with  a  blue  flame. 


Sometimes  contains  little  arsenic. 
More  liable  to  decomposition  than 
ordinary  pyrites. 


94 


CHARACTERS. 

TRVS          MAGNETIC 

COLOS. 

LUSTRE. 

FUSI- 
BILITY. 

HARD- 
NESS. 

BEFORE 

TREATMENT  WITH  ACIDS,ETC. 

ZATION.      HEATING. 

Partially   dissolved    in 

Iron-black. 

Sub- 

Sub-          Infus. 

5-6 

4.5-5         III.       Both.          See  under  heading  IRON,  etc. 

HC1.        Concentrated 

metallic. 

metal- 

solution   boiled    with 

lic,  with 

tinfoil    gradually    as- 

blacker 
brown- 

sumes  a  violet  color. 

red 

powder 

When  heated  in  closed 

Very  pale, 

Splen- 

Brown- 

Easily 

6-6.5 

4.9 

I. 

After. 

Large  amounts  of  sulphuric 

tube  gives  off  sulphur 

brass-like, 

dent, 

black  to 

acid   and    sulphur   are   pre- 

and yields  a  magnetic 

yellow. 

metallic 

green- 

pared  from  pyrites,  though 

residue.     But  slightly 

to  glist- 

ish 
black. 

native  sulphur  (y.  v.)  is  also 

affectedbyHCl.  HNO3 

ening, 

very   largely    used    for   the 

dissolves    it,    leaving 

nearly 

production  of  sulphuric  acid. 

residue  of  sulphur. 

uniform 

It  would  be  difficult  to  over- 

estimate the  commercial  im- 

portance  of  the  latter. 

Same  as  above. 

Pale-yellow, 

Metal- 

Black-     Easily 

6-6.5 

4.8           IV.        After.         Used  for  the  same  purposes 

bronze,  to 

lic. 

ish 

as  ordinary  pyrites,  and  to  a 

white.  Color 

gray  to 

small  extent  in  ;ewelry. 

deepens  on 

ish 

exposure. 

black. 

1 

f 

NAME. 


COMP.  AND 

PERCENTAGE 
OF IMPORTANT 

CONSTITUENT. 


GENERAL  CHARACTERS  AND  ASSOCIATIONS. 


IRON  AND  ITS  COMPOUNDS.— Continued. 


Magnetic  Fe7S8. 
Iron  Py- 
rites Iron,6o.4g. 
(Pyrrho-  Sulphur, 
tite).  39.5*- 

Franklin-     (FeZnMn) 
ite  + 

(Fe2Mna)O4 

Variable. 


Kaolin  or  A12O3, 
Kaolinite  2SiOa  + 

(China-          2H2O. 

clay).  Silica, 

Alumina, 
39-5*- 


Like  common  pyrites,  but  magnetic,  and  different  crystallization. 

Often  contains  nickel.     Tarnishes  quickly. 
Associations  the  same  as  the  foregoing. 


Resembles  magnetite,  but  is  of  a  more  decided  black  color,  and 
different  streak.  Usually  feebly  magnetic.  (See  also  Zinc 
Ores.)  Its  chief  value  consists  in  the  zinc  which  it  contains. 

Found  associated  with  red  oxide  of  zinc  and  garnet  in  granular 
metamorphic  limestone,  also  with  silicate  of  zinc.  Restricted 
to  a  few  localities  near  Franklin,  N.  J. 

The  soapy  feeling  distinguishes  the  clay,  consisting  of  it  or  con- 
taining much  of  it.  The  unctuous  and  plastic  character  is  owing 
to  presence  of  kaolinite.  Decomposition  of  feldspar  yields  it,  etc. 
(See  Dana's  Min.,  p.  636.)  Soft,  clay-like,  mealy,  or  compact. 

Often  occurs  in  the  form  of  scales  in  connection  with  the  iron  ores 
of  the  coal  formation,  also  accompanying  diaspore  and  emery  or 
corundum.  Nearly  always  a  product  of  the  alteration  of  feld- 
spar, and  therefore  associated  with  feldspathic  rocks,  usually 
granite.  Has  frequently  to  be  separated  from  grains  of  quartz, 
with  which  it  is  associated  before  it  is  fit  for  use. 


SPECIFIC 


BEFORE  BLOWPIPE. 


Magnetic  before  fusion  chief  charac- 
teristic, but  variable  in  this.  In 
R.  F.  fuses  to  black  magnetic 
mass.  In  O.  F.  converted  into  red 
oxide. 

On  charcoal  a  faint  zinc  coating  is 
obtained  with  R.  F.  A  soda  mix- 
ture in  outer  flame  colored  green 
by  manganese.  With  borax  reacts 
for  manganese  and  iron. 


A   blue    color   when   moistened    with 
cobalt  nitrate  (Al).     Yields  water. 


96 


CHARACTERS. 

TREATMENT  WITH  ACIDS, ETC. 


COLOR. 


LUSTRE.        STREAK 


Fusi-         HARD- 

BILITY.  NESS. 


.Sp. 


I  I  I 


But    little   sulphur    in     Bronze-yel-       Metal-        Black-     Easily       3.5-          4.5  III.       Both.          Like  ordinary   pyrites,  used 


closed  tube.     Decom-       low  to  cop        lie.              gray.                        4.5                                                              for  making  green  vitriol  and 

posed    by    HC1    with       per-red.                                                                                                                                   sulphuric  acid. 

evolution  of  hydrogen 

sulphide. 

Soluble   in    HC1,    with     Iron-black.       Metal-        Dark       Infus. 

6 

5-15 

I.         Both. 

evoluron  of  chlorine                                 lie  to          red- 

in  small  quantities.                                      dull.           dish 

brown 

to 

black. 

Insoluble      in      acids.     White,  gray,     Pearly        ^ar1t/iy'     Infus. 

2-2.5 

2.6 

V. 

The   purest   form    is   largely 

Yields  water  in  closed       yellow,  and      to  dull, 

used    in    making  the   finest 

tube.       Water  =  14%.      brown  to           earthy. 

porcelain,  and  also  for  giv- 

Boiled   with    concen-      bluish. 

ing  body  and  weight  to  pap- 

trated sulphuric   acid 

er.     Some  impure  and  white 

the    alumina    is    dis- 

clays   are    used    for   stone- 

solved,   leaving     the 

ware,  fire-bricks,  retorts  for 

finely  -  divided     silica 

gas-works,  stove-pipes,  etc.  , 

behind. 

etc.      Also    used    in   calico- 

I 

bleaching,  and  to  a  small  ex- 

tent in  the  manufacture  of 

alum,  artificial  ultramarine, 

and    some    other    chemical 

products.     (See  Fire-clay.) 

97 

NAME. 


COMP.  AND 

PERCENTAGE 
OF  IMPORTANT 
CONSTITUENT. 


GENERAL  CHARACTERS  AND  ASSOCIATIONS. 


SPECIFIC 


BEFORE    BLOWPIPE. 


LEAD  AND  ITS  COMPOUNDS. 

They  are  easily  fusible.  With  borax  bead  and  with  soda,  and  often  alone,  on  charcoal  a  malleable  bead  may  be 
coating  is  faintly  bluish  white  when  cold.  When  S  and  KI  are  added  there  is  a  greenish-yellow  coating  far  from  assay.  Sublimes 
is  nearly  insoluble  in  water  and  dilute  acids.  Heated  in  open  tube,  white  smoke  and  a  non-volatile  fusible  sublimate  is  deposited 
characteristic  coating  will  be  produced  on  the  coal.  But  sulphides,  arsenides,  etc.,  of  lead  must  be  treated  in  O.  F.  to  produce  the 

Assay,  Appendix. ) USES.  —  Perhaps  the  largest  use  of  lead  is  in  the  manufacture  of  the  white  lead  of  commerce  (carbonate  of  lead) 

metallurgical  processes,  as  an  alloy,  e.g.,  with  antimony  in  the  mamtfacture  of  anti-friction  metals  and  type-metal,  -with  tin  in  the  manu- 


Galena         PbS.  Easily  recognized  by  the  characteristic  cubical  cleavage  which  is 

(Galen-  very  easily  obtained,   or  granular  structure   when   massive,   its 

ite).  Lead,  color,  great  weight,  and  softness.     It  is  the  chief  ore  of  lead,  and 

86.6%.  is  widely  distributed,  being  very  frequently  associated  with  other 
metallic  sulphides,  such  as  pyrite,  chalcopyrite,  arsenopyrite, 
blende,  etc.,  etc.  It  occurs  in  veins,  the  gangue  of  which  is 
either  quartz,  calcite,  barite,  or  fluor-spar,  in  granite,  and  nearly 
all  varieties  of  rocks,  but  the  larger  deposits  are  usually  found 
either  in  veins  or  in  pockets,  often  of  great  size,  in  limestone 
strata.  Very  frequently  contains  considerable  percentages  of 
silver,  and  less  frequently  of  gold. 


With  soda  on  coal  decrepitates,  covers 
the  coal  yellow,  and  yields  lead 
globule. 


Cerussite  PbCO9.  Its  brittleness  and  weight  are  distinguishing  characteristics. 

(Lead  NOTE. — The  above  two  ores  often  contain  silver,  q.  v. 

Carbon-  Lead,  Usually  found  in  the  superficial  portions  of  deposits  of  galena,  to 

ate).                       83. 5£.  the  alteration  of  which  it  owes  its  origin. 


Yields  lead  alone  on  charcoal  when 
heated  carefully.  In  closed  tube 
decrepitates,  turns  yellow,  then  a 
dark  red,  and  returns  to  yellow  on 
cooling. 


98 


CHARACTERS. 


TREATMENT  WITH  ACIDS,  ETC. 


LOR. 

LUSTRE. 

STREAK 

FUSI- 
BILITY. 

HARD- 
NESS. 

SP.  GR. 

CF 

TA 

\    "=" 

MAGNETIC 
BEFORE 

OR  AFTER 
ZATION.         HKATING, 


USES. 


characteristic  1« 


obtained.  Readily  recognized  by  characteristic  lemon  or  sulphur-yellow  coating  near  assay  when  cold;  red  when  hot.  The  outer 
readily.  Volatile,  tinging  flame  azure-blue.  In  nitric  acid  solution  of  salts  of  lead  sulphuric  acid  gives  a  white  precipitate,  which 
on  under  side  of  tube.  Oxides,  carbonates,  etc.,  may  be  reduced  to  the  metallic  state  by  heating  in  R.  F.  with  soda,  and  the 
metal.  Metallic  lead  obtained  as  above  may  be  cupelled  for  silver  on  charcoal,  or,  better,  on  a  bone-ash  cupel.  See  B.  B.  Silver 
for  use  in  paint.  It  is  also  largely  made  into  pipes,  sheet-lead,  bullets,  and  shot',  also  extensively  itsed  as  a  flux  in  smelting  and 
facture  of  solder,  etc.,  and  in  the  manufacture  of  certain  kinds  of  glass,  etc. 


Easily  soluble  in  strong     Lead-gray.        Splend-      Lead-           i             2.5           7.5 

I. 

When  ground  to  an  impalpa- 

nitric acid,  with  sepa- 

ent, 

gray. 

ble    powder    and    mixed    in 

ration  of  sulphur  and 

metal- 

water  with  clay  it   is  some- 

the formation  of  lead                                  lie. 

times    employed     for    glaz- 

sulphate. 

ing  common  stoneware,  the 

• 

earthen  vessel  being  dipped 

into    this    liquid    and  then 

baked. 

Dissolves  readily,  with 
effervescence,    in    di- 
lute HNO3.   WithHCl 

White,  yellow- 
ish, or  gray 
or  gray- 

Ada- 
man- 
tine, 

Un- 
col- 
ored. 

Easily 

3-5 

6.4 

IV. 

' 

See  under  heading  LEAD,  etc. 

leaves  a  white  residue       ish  black.          vitre- 

of  lead  chloride,  which       When  con-        ous, 

is  soluble  in  hot  water.       taining  cop-      resin- 

per,  tinged        ous  to 

blue  or                pearly. 

greqn. 

99 

NAME. 


COMP.  AND 
PERCENTAGE 
OF  IMPORTANT 
CONSTITUENT. 


GENERAL  CHARACTERS  AND  ASSOCIATIONS. 


SPECIFIC 


BEFORE  BLOWPIPE. 


MAGNESIUM  AND  ITS  COMPOUNDS, 

These  afford  a  clear  rose  -red  or  pink  color  with  cobalt  nitrate  after  long  heating.  This  distinguishes  it  from 
no  precipitate  in  dilute  HC1  solution.  The  fact  that  the  precipitate  from  magnesia  is  soluble  in  water,  while  that  from  calcium  is 
signalling.  It  is  also  used  in  refining  metals  to  reduce  the  metallic  oxides  contained  in  them,  owing  to  its  great  affinity  for  oxvgen. 
agent,  on  account  of  the  amount  of  magnesia  which  they  contain,  as,  owing  to  their  constitution,  they  have  the  property  of  attracting  the  phos- 
with  it,  and  does  not  remain  in  the  resulting  pig  iron,  as  it  would  otherwise  do. 


(a) 

Chlorites 
(Com- 
mon 
rock 

constitu- 
ents, 
mas- 
sive). 


Serpen- 
tine 
(Mas- 
sive). 


Variable. 


Name  of  a  group  of  minerals  very  closely  allied,  which  are  hydrated  silicates  of  aluminum  with  ferrous 
iron  and  magnesium.  Sometimes  thin  foliated  like  mica,  but  often  granular,  massive.  Texture  granu- 
lar. Enter  very  largely  into  composition  of  schistose  and  slaty  rocks.  Chloritic  schists  and  all  their 
minerals  are  characterized  by  the  green  color  which  "  is  common  with  silicates  in  which  ferrous  iron  is 
prominent  "  (Dana). 

It  occurs  often  in  chloritic  and  in  many  rocks  as  an  alteration  prod- 
uct, and  associated  with  magnetic  hornblende  and  tourmaline. 
Often  enveloped  in  quartz. 


H.MgjSijO,. 

Magnesia 

43*- 
Silica, 

44-1*- 


Usually  compact,  massive,  also  finely  granular.  It  is  a  metamor- 
phic  rock,  the  unaltered  form  being  either  sedimentary  (e.g., 
limestone)  or  igneous  (e.g.,  peridotite)  in  origin,  but  most 
serpentines  are  altered  peridotites.  Rarely  fibrous.  Easily 
scratched  or  even  cut  with  a  knife.  Smooth  and  a  little  greasy 
to  feel.  Hydrated  silicate  of  magnesia.  The  variety  chrysotile 
or  bostonite  is  fibrous,  and  is  largely  mined  as  asbestos,  q.  v. 

Often  in  great  dikes — even  composing  mountain  masses — associated 
often  with  metamorphosed  limestone,  hornblende,  slate,  diallage 
rock,  and  greenstone.  Certain  metallic  oxides  are  frequently 
found  in  connection  with  it,  such  as  those  of  iron,  nickel,  and 
chromium. 

100 


Becomes    brownish    red    B.    B., 
gives  off  water  in  closed  tube. 


and 


CHARACTERS. 

TREATMENT  WITH  ACIDS, ETC. 


COLOR. 


LUSTRE.       STREAK 


FUSI- 
BILITY. 


HARD- 
NESS. 


SP.  GR. 


CRYS- 
TALLI- 
ZATION. 


MAGNETIC 
BEFORE 

OR  AFTER 

HEATING. 


USES. 


alumina.    Distinguished  from  strontia  and  baryta  by  different  flame-colors,  and  in  the  wet  way  by  the  fact  that  sulphuric  acid  gives 

not,  suffices  to    distinguish    it  from   the   latter,  etc. USES. —  The   metal  is  chiefly  used  as  an   illuminant  in  photography  and 

Bricks  made  of  magnesian  limestone  (see  dolomite)  or  magnesite,  are  employed  in  the  steel  industry  as  a  desulphurizing  and  dephosphorizing 
phorus  contained  in  the  iron  ore  while  the  ore  is  being  reduced ;  the  phosphorus  in  consequence  becomes  entangled  in  the  slag  and  goes  off 


Yields  considerable 
water  in  glass  tube, 
which  distinguishes  it 
from  talc,  while  its 
granular  texture  is 
sufficient  to  separate 
it  from  serpentine. 
Decomposed  in  sul- 
phuric acid. 


Dark  olive- 

Pearly, 

Un-         Infus.         1-6 

1.85 

V. 

green, 

opaque 

col- 

grass-green 

to 

ored, 

to  gray- 

partly 

green- 

green, etc. 

trans- 

ish. 

lucent. 

Decomposed  by  HSSO4 
and  HC1,  leaving  resi- 
due of  silica.  From 

Pale  green        Weak          White     Infus. 
to  greenish        resin- 
black,                 ous,  in- 

chrysotile  the  silica  is 
left  in  fine  fibres. 

Sometimes        clining 
mottled.             to 

This  fact  serves  to 
distinguish  the  ser- 
pentine varieties  from 
true  asbestos,  q.  v. 

greasy. 

- 

1 

1 

2-4 


2.5 


101 


See     under     heading     MAG- 
NESIUM, etc. 


Extensively  used  in  orna- 
mental and  architectural 
work,  though  whole  build- 
ings are  sometimes  made  of 
this  stone.  The  finer  varie- 
ties, when  cut  and  polished 
for  ornamental  purposes, 
are  sometimes  termed  mar- 
ble. 


NAME. 


COMP.  AND 
PERCENTAGE 
OF  IMPORTANT 

CONSTITUENT. 


GENERAL  CHARACTERS  AND  ASSOCIATIONS. 


MAGNESIUM  AND  ITS  COMPOUNDS.— Continued. 


Talc 
(Soap- 
stone  or 
Stea- 
tite). 
(Massive 
or  rock 
constitu- 
ent.) 


HaMg8S-40J2 

Magnesia 

31-7*. 
Silica, 

63-5*. 


When  foliated  the  foliae  are  not  elastic.  Very  soft,  scratched  by 
the  finger-nail.  Potstone,  ordinary  soapstone  more  or  less  im- 
pure, which  is  coarse,  granular,  and  is  gray,  grayish,  or  brown- 
gray  in  cojor.  Also  fine  granular,  e.g.,  French  chalk. 

Constitutes  extensive  beds  in  some  regions.  Also  occurs  in  small 
quantities  in  many  rocks.  Frequently  associated  with  serpen- 
tine, talcose  or  chloritic  schists,  and  dolomite,  and  contains 
crystals  of  a  number  of  other  minerals. 


Mag- 
nesite 
(Mas- 
sive). 


MgCO,. 

Magnesia, 

47-6*. 
COa 

=  52.4*- 


White  and  like  calcite  in  appearance,  but  often  occurring  massive, 
and  looking  like  unglazed  porcelain. 

This  mineral  forms  quite  extensive  beds  in  Canada  and  in  Greece, 
and  occurs  in  connection  with  serpentine,  talcose  schists  and 
other  magnesian  rocks,  also  gypsum,  and  is  usually  associated 
with  the  magnesium  minerals,  steatite,  serpentine,  and  dolomite. 
Also  found  in  serpentine,  or  so  admixed  with  the  serpentine  as 
to  form  a  variety  of  verd-antique  marble. 


102 


SPECIFIC 


BEFORE   BLOWPIPE. 


Exfoliates  before  blowpipe.  Mois- 
tened with  cobalt  solution  and 
heated  assumes  a  pale-red  color. 


Infusible. 


CHARACTERS. 


TREATMENT  WITH  ACIDS,  ETC. 


Not  acted  upon  by 
acids.  In  closed  tube 
gives  a  little  water, 
but  not  till  highly 
heated. 


COLOR. 


White,  apple 
to  dark 
green, 
brown, 
grass-  and 
black-green 
when  im- 
pure. 


LUSTRE.       STREAK 


BH!ITY 


HARD- 

NESS. 


SP.GR. 


CRYS 
TALLI- 

ZATION. 


MAGNETIC 


USES. 


Pearly 


White 

or 

lighter 

than 

color. 


Infus. 
or 

above 
5- 


gray, 

brown, 

green. 


(hot    HC1)    gives    no      yellow, 
precipitate  with 

H2SO4.  Compare 

dolomite,  which  gives 
a  precipitate.  Dis- 
solves entirely  in 
H2SO4;  the  other  only 
partially,  but,  like  it, 
it  effervesces  with  hot 
HC1,  but  not  with  cold. 


ous, 
silky. 


I-I-5 


2.7 


IV.  or 
V. 


-4 


J          . 

1ITw.-«._ 

TTJi  

•»irt.:»_ 

T       t  

Steatite  or  soapstone  is  simply  a 
massive  form  of  talc,  and  is  ap- 
plied to  a  great  variety  of  pur- 
poses, but  chiefly  to  the  manu- 

facture  of  fire-brick,  laundry,  bath, 

and  chemical  tubs,  hearthstones,  mantels,  pencils  (French  chalk),  cooking- 
pots,  griddles,  etc.  It  is  carved  into  many  objects,  both  useful  and  orna- 
mental. When  ground  it  is  used  as  polish  in  the  composition  of  mineral 
paint,  in  the  manufacture  of  machinery  lubricants,  for  skin  and  leather 
dressing,  and  as  an  adulterant  for  soap,  for  removing  grease  from  cloth,  etc. 
If  the  powder  be  exceedingly  fine,  it  has  the  property  of  clinging  to  metal 
and  stone  with  great  tenacity,  and  makes  the  finish  which  protects  their 
surfaces  from  the  weather.  It  is  said  to  be  used  with  excellent  results  for 
heating-stoves.  (See  Mineral  Industry,  vol.  2.)  The  principal  use  of  fibrous 
talc  is  in  filling  and  weighting  paper,  to  which  it  gives  strength,  weight,  dura- 
bility, and  finish.  Being  insoluble  and  perfectly  harmless  when  taken  into 
the  system,  it  is  used  quite  extensively  as  an  adulterant  in  medicines.  It  is 
also  largely  mixed  with  cheaper  kinds  of  soap,  and  forms  the  basis  of 
numerous  fire-  and  water-proof  paints  and  plasters. 


3-5-4-5        3-12 


III. 


103 


Besides  being  used  for 
hearths  in  the  "Basic" 
processes  in  manufacturing 
steel  as  described,  it  is  used 
quite  largely  as  a  bleaching 
agent  in  the  manufacture  of 
paper  from  wood-pulp  and 

in  the  construction  of  portions  of  fire-proof 
buildings.  It  is  also  used  in  the  manufacture 
of  Epsom  salts  (sulphate  of  magnesia)  and  for 
other  chemical  purposes. 


NAME. 


COMP.  AND 
PERCENTAGB 
OF  IMPORTANT 
CONSTITUENT. 


GENERAL  CHARACTERS  AND  ASSOCIATIONS. 


SPECIFIC 


BEFORE  BLOWPIPE. 


MANGANESE  AND  ITS  COMPOUNDS. 

These  are  readily  recognized  by  the  characteristic  amethystine  color  oxide  of  manganese  imparts  to  beads  of  borax  and  salt 
when  cold.  With  salt  of  phosphorus,  brown-violet  when  hot,  pale-red  violet  when  cold.  Do  not  confuse  with  the  pale  violet 
bead  opaque.  With  soda  in  O.  F.  on  platinum  wire,  or,  preferably,  platinum  foil,  the  color  is  green  or  bluish  green.  Most  varieties 

brown   hematite   (limonite)  and    less   often    with    varieties   of  red    hematite  or  magnetite. USES. — Over  nine  tenths  of  the 

used  in  the  manufacture  of  steel,  since  manganese  imparts  to  the  steel  not  only  hardness,  but  a  high  degree  of  toughness  and  disability.     It 
only  the  very  pure  ores  are  used. 


Pyrolu-        MnO».  The  common  ore.     Soft  and  soils  fingers.     Distinguished  by  its 

site.  color,  softness,  etc.     Nodular  and  in  layers.     Compact  to  uncon- 

Manga-  solidated,  etc. 

nese,  Usually  occurs  in  connection  with  psilomelane,  both  crystallized 

63. 2#.  and   massive.     Often  in  connection  with  limonite,  both   being 
secondary  minerals  due  to  the  leaching  of  the  rock  containing 

I  manganese  and  iron. 


Gives  manganese  reaction. 


Psilome- 
lane. 


Variable.        Usually  harder  than  the   foregoing,  with   which  it  is  often  asso-   Reacts    for    manganese.      Generally 


ciated.  Usually  more  or  less  admixed  with  barium  and  potas- 
sium, especially  the  former.  Compact  and  usually  smooth. 
Nodular,  botryoidal,  and  mammillary,  massive  and  stalactitic. 
Tendency,  like  limonite,  to  acicular  concretionary  forms.  Much 
resembles  above,  except  that  it  affords  water,  and  is  much  harder 
and  contains  less  manganese. 

Like  the  above,  often  associated  with  limonite  in  segregated 
masses  in  clay  due  to  the  decomposition  of  limestones  and  other 
rocks  containing  manganese  and  iron. 


gives  barium  flame,  yellowish  green 
when  heated  in  forceps. 


104 


CHARACTERS. 


TREATMENT  WITH  ACIDS,ETC. 


COLOR. 


LUSTRE.       STREAK 


FUSI- 
BILITY. 


HARD- 
NESS. 


SP.  GR. 


CRYS- 
TALLI- 
ZATION. 


1 — — — r — r 


MAGNETIC 
BEFORE 

OR  AFTER 

HEATING. 


USES. 


' 


of  phosphorus  in  O.  F. ;  colorless  in  R.  F.  With  borax  the  color  becomes  violet,  amethystine,  or  purple  when  hot,  amethystine 
color  imparted  to  beads  by  presence  of  titanic  acid,  which  only  appears  on  heating  in  R.  F.  Too  large  a  quantity  renders 
are  soluble  in  hydrochloric  acid  with  evolution  of  chlorine.  The  oxides  are  frequently  associated  with  ores  of  iron,  especially 
manganese  that  is  produced  is  used  in  the  manufacture  of  the  alloys  of  iron  and  manganese,  known  as  ferromanganese  or  spiegeleisen, 
is  used  to  a  small  extent  in  bleaching,  and  also  in  calico-printing,  dyeing,  and  to  give  a  violet  color  to  glass  and  pottery,  for  which  purposes 


HC1  dissolves   it,  with     Iron-black,       Metal-        Black,       Infus.        2.5          4.82          IV.                           See   under  heading   MANGA 

evolution  of  chlorine.      dark  steel-        lie,  sub-      H"*^1 

NESE,  etc. 

No    water    in    closed      gray  to               metal- 

tube,                                     bluish.               lie.               times" 

shin- 

, 

ing. 

In    HC1    solution    sul-     Iron-black         Subme-      Black-      Infus.        5-6 

4.2 

Amor- 

See   under  heading  MANGA 

phuric      acid      yields      to  dark               tallic. 
white    precipitate    of      steel-gray. 

phous 

NESE,  etc. 

sulphate     of    baryta. 

Some- 

Yields much  water  in 

times 

closed  tube. 

shin- 

ing. 

1 

35 

NAME. 


COMP.  AND 

PERCENTAGE 
OF  IMPORTANT 
CONSTITUENT. 


GENERAL  CHARACTERS  AND  ASSOCIATIONS. 


MANGANESE  AND  ITS  COMPOUNDS.— Continued. 

Braun-        3MnaOs  Massive,  and  often  associated  with  the  above  species, 

ite.  +MnSiOs. 

Sometimes 
Mn,O3. 


SPECIFIC 


BEFORE  BLOWPIPE. 


Reacts  for  manganese. 


Manga- 
nite. 

Manganese, 
63.6*. 

Mn2O3. 
H2O. 

Manga- 
nese, 
62.  4*. 

Prismatic  cleavage,  sometimes  perfect.     Brittle.     Comparatively     Reacts  for  manganese 
rare.     By  loss  of  water  it  changes  into  pyrolusite,  braunite,  or 
hausmannite. 
Occurs  sometimes  in  veins    traversing  porphyry  and  associated 
with  calcite  and  barite. 

Haus- 
mannite. 

MnsO4. 

Manganese, 
71-9*- 

Rare  and  unimportant.                                                                                       Reacts  for  manganese. 
Sometimes  occurs  in  porphyry  along  with  other  manganese  ores. 

Wad 
(Bog 
Manga- 
nese). 

Variable. 
HsMn2O6. 

Earthy  variety  and  common,  but  of  small   importance.     Soft,  and     Reacts  for  manganese, 
soils  fingers.     Usually  mixed  with  silica,  baryta,  alumina,  and 
iron    oxide,    sometimes   nickel  and   cobalt.      Light   in    weight. 
Rarely  hard  in  reniform  masses. 
Occurs  as  a  marsh  deposit,  and  is  the  result  of  the  decompositions 

of  the  other  ores.     Sometimes  contains  oxide  of  cobalt  as  well  as  oxide  of  copper.     Sometimes  also 
contains  oxide  of  nickel  besides  the  other  two,  with  iron,  lead,  and  sulphur.    Usually  contains  from  10* 
to  25;{  water.     Can  hardly  be  regarded  as  distinct  mineral  species. 

106 


CHARACTERS. 
COLOR.               LUSTRE.        STREAK      BILJTY 
TREATMENT  WITH  ACIDS,ETC. 

-      —  ,   _    _   -      .-,,-       1-   r,-,rr-|  ,                                                                                                        * 

HARD- 
NESS. 

CRYS-       MAGNETIC 

SP-GR-        ™£          OREISL                                           USES" 

*••*»  *IV/W.                 HIT  »  TfKtf~ 

IIC.A  i  IN*./, 

I 

. 

Dissolves  in  HC1,  etc.,     Dark                   Subme-      Same       Infus.        6.5           4.7           II.                            See   under   heading   MANGA- 

leaving   a   residue  of      brown-               tallic.         as                                                                                                NESE,  etc. 

gelatinous    or    floccu-      black  to 

color. 

lent  silica.                           steel-gray. 

J 

In   closed    tube   yields     Dark  steel-       Subme-      Red-         Infus. 
much    water,    and    in      gray  to               tallic.         dish  or 

4 

4-3 

IV. 

See   under  heading  MANGA- 
NESE, etc. 

this   differs   from   the      iron-black. 

following.    Otherwise 

•V,    A 

nished 
browD 

like  the  above. 

to 

_l_ 

black. 

tallic.          nut- 
brown. 


5-5.5         4.7 


NESE,  etc. 


.1 
Gives    much   water   in     Dove-gray,       Earthy,      Red-        Infus.     Soft 


closed  tube. 


bluish 
black, 
brown  to 


dull. 


dish 
brown. 


to 

rarely 

6. 


black. 

107 


Amor- 
phous 


Sometimes   used  for  bleach- 
ing and  for  umber  paint. 


NAME. 


COMP.  AND 

PERCENTAGE 
OF  IMPORTANT 

CONSTITUENT. 


GENERAL  CHARACTERS  AND  ASSOCIATIONS. 


MANGANESE  AND  ITS  COMPOUNDS.— Continued. 


SPECIFIC 


BEFORE  BLOWPIPE. 


Rhodo- 

MnCO3.           B 

chrosite 

(Carbon- 

Manga- 

ate of 

nese, 

Manga- 

47-8*. 

nese). 

(Dialo- 

gue.) 

Rhodo- 

MnSiOs.         1 

nite 

(Manga- 

Manga- 

nese 

nese, 

Spar). 

4I-9*- 

(Silicate 

of  man- 

1 

ganese.) 

Common 

vein- 

stone. 

•• 

Manganspath.  Usually  pink  or  rose-red  color.  Often  calciferous, 
ferriferous,  and  sometimes  zinciferous.  Occurs  in  veins  with 
other  metallic  ores,  such  as  those  of  silver,  lead,  or  copper,  or 
associated  with  other  ores  of  manganese.  Sometimes  in  strati- 
fied or  bedded  masses.  The  above  oxide  ores  are  in  some  cases 
resultant  from  the  oxidation  of  original  carbonate  ore.  It  is 
quite  largely  mined  in  France,  but  is  roasted  and  thus  con- 
verted into  the  commercial  oxide  before  being  shipped. 

Manganese  Spar.  Often  dark  brown  or  black  on  surface, 
"  through  strong  tendency  of  manganese  protoxide  to  pass  to  a 
higher  state  of  oxidation."  Somewhat  resembles  red  feldspar, 
but  readily  distinguished  by  its  behavior  B.  B.  and  with  acids. 
On  exposure  to  air  oxidizes  rapidly,  the  outcrop  of  many 
metalliferous  veins  appearing  black  in  consequence. 

Frequently  found  in  the  western  United  States  in  fissure  veins  and 
similar  deposits  in  connection  with  and  as  the  gangue  of  the 
ores  of  silver,  lead,  gold,  copper,  etc. 


Changes  color  to  gray  or  brown  or 
black.  Decrepitates  strongly  and 
gives  manganese  reaction.  Infusi- 
ble. 


Fuses  quietly  at  3.  Gives  manganese 
reaction.  When  heated  becomes 
dark  brown. 


MERCURY  AND  ITS  COMPOUNDS. 

Mercury,  or  quicksilver,  and  its  amalgams  volatilize  on  charcoal,  but  give  a  sublimate  of  metallic  mercury  when  heated  in 
brushed  together  with  a  feather,  etc.  When  a  gray  sublimate  is  obtained  without  distinct  metallic  globules,  the  part  of  the  tube 
case  mercury  exists  in  so  small  a  quantity  that  the  sublimed  metal  is  not  perceptible,  it  may  be  detected  by  inserting  a  piece  of 
gold,  giving  it  a  white  color.  The  ores  follow. 


108 


CHARACTERS. 


TREATMENT  WITH  ACIDS.ETC. 


COLOR. 


LUSTRE.        STREAK 


FUSI- 
BILITY. 


HARD- 
NESS. 


SP.  GR. 


CRYS- 
TALLI- 
ZATION. 


MAGNETIC 

BEFORE 
OR  AFTER 

HEATING. 


USES. 


Soluble  in  heated  HC1, 

Rose-red,          Vitre-         White     Infus.         4            3.5          III.                          See  under  heading   MANGA- 

with        effervescence. 

yellowish,         ous,                                                                                                                     NESE,  etc. 

On    exposure    to    air 

gray,                   pearly. 

changes    to  brown  or 

brown, 

bright    rose-red;    va- 

fawn color, 

rieties  become  paler. 

and  deep 

red. 

Slightly    attacked     by 

Rose-red    to     Vitre-         Un-          2.5-3          6            3.6          VI.                          See   under   heading   MANGA- 

HC1.     Does  not  effer- 

brown.              ous.             col- 

NESE,  etc. 

vesce    like    preceding 

ored. 

unless   admixture    of 

CaCO3  is  present.    In 

powder  partially  dis- 

• 

solves    in     HC1,    the 

residue          becoming 

white. 

closed  tube  with  or  without  soda;  best  with  soda.  The  metal  condenses  above  assay  in  globules  on  the  tube.  These  may  be 
coated  with  it  is  cut  off  and  boiled  in  a  test-tube  with  a  little  dilute  HC1.  By  this  treatment  mercury  collects  in  shining  globules.  In 
gold-leaf,  held  on  end  of  iron  wire,  into  the  tube  just  above  assay.  On  heating,  the  mercury  is  volatilized  and  unites  with  the 


109 


NAM:;. 


COMP.  AND 
PERCENTAGE 
OF  IMPORTANT 
CONSTITUENT. 


GENERAL  CHARACTERS  AND  ASSOCIATIONS. 


MERCURY  AND  ITS  COMPOUNDS.— Continued. 

Native.         Hg.  Occurs  in  small  liquid  globules,  probably  resultant  from  the  follow- 

ing by  some  secondary  reaction,  scattered  throughout  its  gangue. 
The  other  ores  frequently  contain  it. 

It  also  sometimes  occurs  alloyed  with  silver,  when  it  forms  native 
amalgam  in  combination  with  sulphur  and  antimony  in  tetra- 
hedrite. 


SPECIFIC 


BEFORE   BLOWPIPE. 


Entirely  volatile,  going  into  vapor 
at  350°  C.  (662°  F.).  Solidifies 
and  crystallizes  into  octahedra  at 
—  38°. 8  C.  (—  37°. 9  F.),  when  it  be- 
comes soft  and  malleable. 


Cinna- 
bar. 


HgS. 

Mercury, 

86.2*. 


Calomel. 


Mercury, 
84.9*. 


The  common  ore  of  quicksilver.  Distinguished  from  realgar  by 
the  alliaceous  fumes  of  the  latter  on  charcoal  and  other  charac- 
teristics. Usually  admixed  with  clay,  iron  oxide,  or  bitumen. 
Somewhat  sectile. 

Occurs  chiefly  in-  veins  in  slate  rocks,  shales,  and  schists,  both  the 
most  ancient  and  the  more  recent.  These  rocks  are  often  meta- 
morphic,  and  dikes  of  eruptive  material  are  usually  found  in  close 
proximity.  It  is  also  sometimes  found  ill,  granite,  sandstone, 
limestone,  and  porphyry.  The  associated  minerals  are  pyrite, 
marcasite,  sulphides  of  copper,  stibnite,  realgar,  gold,  etc.  The 
gangue  minerals  are  usually  calcite,  quartz,  barite,  and  fluorite. 
It  is  usually  not  found  in  large  quantities  in  crystalline  or 
igneous  rocks. 

Tough  and  sectile.     (Rare.) 
Occurs  with  cinnabar. 


, 


ntirely  volatile  unless  admixed  with 
gangue  (quartz,  calcite,  etc.,  etc.). 


Volatilizes  on   charcoal,  coating  the 
coal  white. 


110 


CHARACTERS. 

• 

r~  „.          MAGNETIC 

COLOR. 

LUSTRE.        STREAK        ^usi-         HARD-       Sp  GR        TA^U-        ^FTRR                                   USES* 

TREATMENT  WITH  ACIDS,  ETC. 

ZATION.         HEATING 

Dissolves     readily     in     Tin-white. 

Bril-                            Vol. 

14.4 

I. 

It  is  largely  used  in  the  ex- 

nitric  acid. 

liant 

traction    of  gold  and  silver 

metal- 

from their  ores  bv  amalga- 

lic. 

mation,  to  a  less  degree  in  silvering  mirrors,  for  thermometers  and  barometers, 

and  for  many  purposes  in  the  arts,  in  the  laboratory,  and  in  medicine,  e.g.,  as 

bichloride  of  mercury,  the  best  antiseptic  preparation  known,  calomel,  etc. 

Mixed    with    soda     in     Red  to   red- 

Unme-        Scar-         Vol.        2-2.5         8.9           III.                           The   paint  vermillion,  which 

closed  tube  gives  me- 

dish brown. 

tallic  to      let-                                                                                                  is  used  largely  in  printing, 

tallic      mercury,     but 

Some  varie- 

dull             red. 

lithographing,   etc.,   is   pre- 

alone  a   black    subli- 

ties gray  or 

and 

• 

pared  from  this  ore,  having 

mate.     In    open    tube 

black,      but 

earthy; 

the  same  chemical  composi- 

gives reaction  for  sul- 

streak red. 

crystals 

tion  as  the  ore. 

phurous   acid,    and  if 

ada- 

carefully heated,  mi- 

man- 

nute globules  of  me- 

tine. 

tallic  mercury,  which 

condense  on  the  cold 

portion  of  the  tube. 

In   nitric    solution    ni-     Gray-white, 

Ada-           Yel-          Vol.          1-2          6.4           II. 

Of  great  value  in  medicine. 

trate   of   silver   gives 

yellowish 

man-          low- 

heavy    precipitate    of 

gray  to 

tine,           ish 

chloride  of  silver.     In 

b'owri. 

white. 

closed  tube  volatilizes 

without     fusion     and 

forms     white     subli- 

mate. 

111 


NAME. 


COM  p.  AND 
PPKCKNTAGE 
OF  IMPORTANT 
CONSTITUENT. 


GENERAL  CHARACTERS  AND  ASSOCIATIONS. 


MEBCUEY  AND  ITS  COMPOUNDS.— Continued. 


Colora- 
doite 
(Mer- 
cury 
Tellu- 
ride). 



Mica 
(Musco- 
vite). 
(Isin- 
glass.) 
Common 
rock 
con- 
stituent. 


HgTe. 

Mercury, 
61.5*. 


Rare.    Found  sparingly  in  Colorado  with  gold  tellurides. 
granular. 


Massive. 


Various.  Foliated.  Very  elastic,  and  is  susceptible  of  being  separated  into 
a  great  number  of  very  thin  sheets.  Physical  characters  readily 
recognized.  Foliae  tougher  and  harder  than  those  of  talc  or 
chlorite.  The  latter  are  non-elastic.  Sometimes  in  large  plates, 
when  it  possesses  considerable  value  and  is  extensively  mined. 
It  is  a  very  common  mineral,  and  is  one  of  the  essential  constitu- 
ents of  ordinary  granite.  It  is  found  in  most  granites  and 
gneisses,  and  in  dikes  of  coarse  granite  traversing  a  granitic 
country  rock,  or  in  gneiss,  mica  schist,  porphyritic  granite, 
etc.;  sometimes  in  granular  limestone.  The  variety  known  as 
amber  mica  or  black  mica,  which  is  common  in  Canada,  is  biotite 
or  magnesium  iron  mica.  This  is  usually  highly  colored  by 
oxide  of  iron,  and  this  variety  supplies  nearly  the  total  supply 
of  commerce  where  transparency  is  not  required.  See  Uses. 
Usually  associated  with  such  minerals  as  quartz,  feldspar,  beryl, 
tourmaline,  garnet,  columbite,  and  samarskite.  Cassiterite  is 
the  associated  mineral  in  the  Black  Hills,  S.  D.,  and  apatite  is 
found  in  connection  with  the  mica  deposits  in  Canada.  It  is  not 
uncommon  in  sedimentary  rocks  such  as  micaceous  sandstones, 
grits,  shales,  etc. 


112 


Sl'HCIFTC 


BEFORE  BLOWPIPE. 


In  tube  decrepitates,  fuses,  and  yields 
metallic  mercury,  as  well  as  drops 
of  tellurium  dioxide. 


.  B.  fuses  with  difficulty  on  edges  of 
very  thin  scales  to  a  gray  or  yellow 
glass. 


CHARACTERS. 

TREATMENT  WITH  ACIDS,  ETC. 


COLOR.  LUSTRE.       STREAK 


FUSI- 
BILITY. 


HARD- 
NESS. 


SP.  GR. 


CRYS- 
TALLI- 
ZATION. 


MAGNETIC 
BEFORE 

OR  AFTER 

HEATING. 


Soluble  in  nitric  acid.       Grayish 

Metal- 

Gray- 

Vol. 

3 

8.6 

Amor- 

black  or             lie.               ish.                                                        phous 

iron-black. 

• 

"     ' 

Not     acted    upon     by     Colorless,          Pearly,       White 

Above 

2-2.5 

2.8          IV. 

acids.     In  closed  tube      white,                 trans-         orun-      5. 

yields  water.                       gray,                   parent        col- 

brown,               to                ored. 

yellow,  red,      trans- 

and  green.         lucent. 

•'•;. 

\ 

USES. 


See  under  heading  MERCURY, 
etc. 


Mica  was  formerly  used  in 
Siberia  as  a  constituent  for 
glass  in  windows,  whence  it 
has  been  called  Muscovy 
glass.  It  is  in  common  use 
in  lanterns,  for  the  doors  of 
stoves  and  furnaces,  and 
other  like  purposes  where  a 
transparent  substance  not 
easily  affected  by  heat  is  de- 
sirable. When  pulverized  it 
is  used  in  the  manufacture  of 
wall-paper  in  order  to  give  a 
glistening  effect.  The  con- 
sumption of  mica  is  increas- 
ing largely  at  the  present 
time,  owing  to  the  fact  that 
usually  when  more  or  less 
finely  ground  it  finds  many 
uses  in  electrical  appliances, 
being  an  excellent  noncon- 
ductor and  insulator. 


113 


NAME. 


COM  p.  AND 
PERCENTAGE 
OF  IMPORTANT 
CONSTITUENT. 


SPECIFIC 


GENERAL  CHARACTERS  AND  ASSOCIATIONS. 


BEFORE  BLOWPIPE. 


MOLYBDENUM  AND  ITS  COMPOUNDS, 

With  borax  bead  in  O.  F.  colorless  when  hot;  faint  yellow  when  cold.     With  saturation  the  bead  becomes  in  R.  F.  an  opaque 
certain  chemical  operations  and  analytical  work,  e.g.,  in  the  detection  of  phosphoric  acid,  etc. 


Molyb- 
denite. 


MoSj.  Very  soft  and  sectile.     Soils  fingers  or  paper  like  graphite  (q.  v.), 

and  looks  much  like  it.     Laminae  very  flexible,  but  not  elastic. 
Molybde-        Occurs  in  granite,  gneiss,   syenite,  mica  schist,  and   other  allied 
num,    60$.         crystalline  rocks;  also  in  granular  limestone,  either  imbedded  in 
the  rock  or  disseminated  through  it.     Usually  associated  with 
scheelite  and  apatite,  and  sometimes  with  zircon. 


Molyb- 
date  of 
Lead 
(Wulfen- 
ite). 


Mona- 
zite. 


In  forceps  colors  flame  light  green  or 
yellowish  green,  which  readily  dis- 
tinguishes it  from  graphite.  This 
effect  is  assisted  if  it  is  first  moist- 
ened with  H2SO4. 


PbMoO4. 

Molybde- 
num, 

26. 2 


Phosphate 
of   the  ce- 
rium 
metals, 
essentially 
(Ce.La.Di) 
P04. 

Variable. 
(See  Bar 
na's  Min.) 


Heated  on  platinum-foil  with  drops  of  strong  sulphuric  acid  until 
copious  fumes  escape  and  allowed  to  cool,  then  breathed  upon, 
acquires  an  ultramarine-blue  color.  Brittle.  Occurs  with  other 
ores  of  lead,  but  is  rare  and  unimportant. 

Sometimes  associated  with  vanadinite,  pyromorphite,  etc.,  upon 
crystalline  limestone. 

Found  in  the  form  of  sand,  and  being  sometimes  distributed  quite 
abundantly  as  an  accessory  constituent  of  gneissoid  rocks  in  cer- 
tain regions.  Found  as  rounded  grains  of  sand  in  gold-wash- 
ings, as  in  North  Carolina  and  Brazil.  Sometimes  known  as 
thorium  sands.  As  its  name  signifies,  it  is  a  rare  mineral. 


Decrepitates  and  fuses  below  2.  With 
metallic  lead;  with  salt  of  phos- 
a  yellowish-green  glass,  which  in 
green  with  black  flocks.  Solution 
if  diluted  with  water,  and  upon 
zinc  and  agitated,  becomes  blue. 

Infusible,  turns  gray,  and  when 
moistened  with  sulphuric  acid 
colors  the  flame  green.  With  borax 
gives  a  yellow  bead  when  hot  and 
colorless  on  cooling.  A  saturated 
bead  becomes  enamel-white  on 
flaming.  (Dana.) 


114 


CHARACTERS. 

TREATMENT  WITH  ACIDS,  ETC. 


COLOR.        LUSTRE. 


STREAK 


FUSI- 
BILITY. 


HARD- 

NESS. 


SP.  GR. 


CRYS- 
TALLI- 
ZATION. 


MAGNETIC 

BEFORE 
OR  AFTER 

HEATING. 


USES. 


Heated  in  platinum 
spoon  with  nitre  ex- 
plodes, with  evolution 
of  light  and  heat.  In 
open  tube  sulphurous 
fumes  and  a  pale  yel- 
low sublimate. 

soda  on  charcoal  yields 
phorus  in  O.  F.  gives 
R.  F.  becomes  dark 
in  HC1  greenish, which, 
addition  of  tin-foil  or 


Soluble  with  difficulty 
in  HC1. 


Lead-gray 

Metal-        Lead- 

Infus.      1-1.5         4-8          III. 

< 

to  blackish.      lie.             gray 

. 

or 

green- 

ish. 

5     White,  red,       Resin-        White 
j      gray-green,      ous  or 
:      but  gener-         ada- 

I-I.5          3            6.9 

II. 

< 

,      ally  yellow-      man- 

ish. 

tine. 

4-  ^- 

'     Hyacinth- 

Inclin-        Whit- 

Infus.      5-5.5       5-5.2         V 

r 

red,  clove-        ing  to         ish  or 

brown, 

resin-         same 

reddish  or         ous.            as 

yellowish 

Sub-           color. 

brown. 

trans- 

parent 

to  sub- 

trans- 

ucent. 

See  under  heading  MOLYBDE- 


NUM, etc. 


See  under  heading  MOLYBDE- 
NUM, etc. 


The  chief  use  of  this  mineral 
is  in  the  manufacture  of 
cylindrical  hoods  or  man- 
tles used  in  the  Welsbach 
light.  (See  Rep.  U.  S. 
Geol.  Sur.  1894-95,  Part  IV., 
Min.  Res.) 


115 


NAMK. 


COMP.  AND 

PERCENTAGE 
OF  IMPORTANT 
CONSTITUENT. 


SPECIFIC 


GENERAL  CHARACTERS  AND  ASSOCIATIONS. 


BEFORE  BLOWPIPE. 


NICKEL  AND  ITS  COMPOUNDS. 

With  borax  the  presence  of  nickel  in  O.  F.  renders  bead,  when  hot,  purplish,  with  a  tinge  of  violet  ;  when  cold,  reddish 
added,  and  the  bead  be  again  heated  in  O.  F.,  a  well-marked  purple  color  is  produced.  Roast  belore  making  above  tests.  Arsenical 
from  cobalt,  but  acquires  a  brown  color,  which  is  violet  when  hot,  the  metallic  globule  is  separated  from  the  borax  and  treated 
both  hot  and  cold.  Treated  with  tin  on  charcoal  it  will  become  red  and  opaque  on  cooling.  Black  sulphides  insoluble  in  dilute 
potash  slowly  precipitates  the  green  hydrate  of  nickel.  Potash  produces  this  precipitate  from  all  ordinary  nickel  solutions. 
in  many  of  the  so-called  white  alloys,  e.g.,  with  copper  and  zinc  forming  German  silver.  The  so-called  "nickel  silver"  alloy  is  largely 
forming  a  clean  white  alloy  it  is  well  adapted  for  coinage  when  the  intrinsic  value  of  the  metal  employed  is  not  to  be  considered,  The  chief 
purposes. 


Copper-       NiAs. 
nickel 

(Nicco-        Nickel, 
lite).  43-9#' 

Arsenic, 

56.1*. 


Gives  off  arsenical  fumes,  and  fuses 
to  pale  globule,  which  darkens  on 
exposure  and  which  affords  by  suc- 
cessive oxidation  reactions  for  ircn, 
cobalt,  and  nickel. 


Of  a  pale  copper-red  color  and  brittle,  and  often  contains  iron, 
cobalt,  and  sulphur.  Often  found  in  Chile  and  Argentine  Re- 
public. Cloanthite  (see  Smaltite)  is  an  important  variety.  This 
is  the  diarsenide  of  nickel  (nickel  28.1^),  often  called  white 
nickel,  and  is  tin-white  with  a  grayish-black  streak.  If  much 
cobalt  is  present  it  graduates  into  smaltite.  Usually  accom- 
panies cobalt,  silver,  and  copper  ores. 

NOTE. — All  these  ores  are  likely  to  be  largely  associated  chiefly          __ 

with  arsenic  and  cobalt,  but  as  well  with  iron,  lead,  copper,  silver,  etc.     When  arsenic  is  drawn  off 
from  combinations  of  nickel  and  cobalt  the  residue  has  the  name  of  Speiss. 

N.  B. — The  ores  of  nickel  are  more  generally  distributed  in  the  United  States  than  is  usually  supposed. 
They  occur  in  small  quantities  in  close  association  with  the  chrome  ores  in  both  eastern  and  western 
portions  of  the  United  States,  and  nickel  is  abundantly  found  throughout  the  serpentine,  steatite, 
diallage,  and  actinolite  of  the  Quebec  group  in  Canada,  and  also  in  certain  of  the  magnesites  and  in  the 
Laurentian  gneiss.  The  close  connection  of  this  element  and  iron  is  not  confined  to  terrestrial  min- 
erals, as  nickel  is  found  in  all  of  the  iron  composing  meteorites.  Nickel  ores  are  usually  found  in  or  in 
close  connection  with  serpentine  rocks,  but  at  Sudbury,  Ontario,  it  is  found  in  a  belt  of  Huronian  rocks 
which  contain  many  inliers  of  gneiss  and  red  quartz-syenite.  The  ore  occurs  in  both  formations,  and  is 
a  mixture  of  chalcopyrite  and  nickeliferous  pyrrhotite.  Millerite  is  sometimes  found  in  association, 
and  also  sperrylite  (arsenide  of  platinum,  q.  v.). 

116 


CHARACTERS. 

TREATMENT  WITH  ACIDS, ETC. 


COLOR. 


LUSTRE.        STREAK 


Fusi-         HARD- 

BIL1TY.  NESS. 


MAGNETIC 
BEFORE 

ORA,™ 


USES. 


In  R.  F. 


ly  and  turbid,  with  reduced  nickel  (use  lens).     If 


sherry-brown.  In  R.  F.  the  bead  becomes  purplish-gray  and  turbid,  with  reduced  nickel  (use  lens).  If  a  fragment  of  nitre  be 
compounds  of  nickel,  cobalt,  iron,  and  copper  are  treated  with  glass  of  borax  (see  Cobalt) ;  when  borax  is  no  longer  colored  blue 
with  salt  of  phosphorus  in  O.  F.  If  copper,  as  well  as  nickel,  be  present  in  the  assay,  the  glass  thus  obtained  will  be  green,  while 
HC1.  (See  Cobalt.)  Nitric  solutions  are  apple-green.  Excess  of  ammonia  produces  a  violet-blue  liquid,  from  which  caustic 

USES. —  The  uses  of  this  metal  have  rapidly  extended.      It  is   used  largely  for  nickel-plating  by  electro-deposition,  and  as  an  alloy 

manufactured  in  the  form  of  ingots,  sheets,  and  wires,  and  is  used  in  the  manufacture  of  spoons,  forks,  plated  ware,  etc.  Owing  to  its 
and  rapidly  increasing  use,  however,  is  in  the  manufacture  of  nickel  steel  for  armor-plate  and  for  other  military  and  industrial 


. 

Aqua  regia  solution  ap- 
ple green.  If  excess 
of  ammonia  be  added 
this  becomessapphire- 
blue. 

Copper  red 
with  black- 
ish-gray 
tarnish. 

Metal- 
lic. 

Pale 
brown- 
red  to 
brown- 
black. 

Easily 

5-5 

7-5' 

III. 

After. 

See   under  1 
etc. 

i 

4 

t 

L7 

J.] 

NAME. 


COM  p.  AND 

PERCENTAGE 
OF  IMPORTANT 
CONSTITUENT. 


GENERAL  CHARACTERS  AND  ASSOCIATIONS. 


NICKEL  AND  ITS 

Genthite. 
Impure 


SPECIFIC 


BEFORE  BLOWPIPE. 


H4(Ni,Mg)< 
Si30ia. 


vari- 
eties— 
Garnier- 
ite,  etc. 
Noume- 
ite. 


Emerald 
Nickel 
(Zara- 
tite). 
(Nickel 
Carbon- 
ate.) 


Pentland- 

ite. 


Variable. 
See  de- 
scription. 


3NiO,CO, 
+  6H2O. 

Nickel, 

46.7*. 


(Fe,Ni)S. 

Nickel, 

39- 9*- 


Reacts  for  nickel.  In  O.  F.  with 
borax,  violet  bead  becoming  red- 
brown  on  cooling,  which  bead, 
when  treated  in  R.  F. ,  becomes 
gray  from  reduced  nickel. 


COMPOUNDS.— Continued. 

The  large  supply  from  New  Caledonia  is  derived  from  garnierite, 

which  is  pale  green  and  adhesive  to  the  tongue,  and  noumeite, 

which  is  dark  green  and  unctuous.     These  ores,  which  are  hy- 

drated  silicates  of  magnesium  and  nickel,  are  amorphous,  soft, 

and  friable,  have  a  dull  lustre, and  vary  from  bright  apple-green 

in  color  to  nearly  white. 
Found   in  veins  in  decomposed  rocks  of   eruptive  origin,  among 

which  serpentine  is  the  most  important.     The  New  Caledonia  ore,  as  exported  for  treatment,  averages} 

^%  to  io<<  nickel.     It  is  frequently  associated  with  chrome  iron  ore  and  oxide  of  cobalt.      It  is  sometimes] 

found  in  taicose  schist  and  associated  with  phosphate  of  nickel. 

Incrusting,    also   massive,    compact,   minutely   mammillated,  and     Becomes    magnetic,    and     gives    the 


stalactitic. 

Usually  containing  variable  quantities  of  sulphur,  associated  with 
chromic  iron,  cobalt  ores,  and  magnetite  in  serpentine  rocks. 


nickel  reaction  with  borax. 


Sulphides  of  iron  and  nickel.  Has  an  uneven  fracture  and  an 
octahedral  cleavage.  Not  magnetic,  and  is  brittle. 

Sudbury,  Ont.,  etc.,  where  also  an  ore  which  corresponds  generally 
to  Ni3FeS5  is  found.  The  usual  ore  of  the  Sudbury  district  is  a 
mixture  of  chalcopyrite  and  nickeliferous  pyrrhotite,  the  per- 
centage of  nickel  in  the  latter  varying  from  i%  to  3^  (Min.  /«</.). 
See  supra. 

Usually  occurs  in  close  association  with  chalcopyrite. 


Roasted  on  charcoal  gives  with  fluxes 
reactions  for  nickel  and  iron. 


CHARACTERS. 


TREATMENT  WITH  ACIDS,  ETC. 


COLOR.  LUSTRE. 


CRYS-       MAGNETIC 

ZATION.         ?fE*™ 


UsES. 


- 

In  closed  tube   black- 

Apple to 

Resin- 

Green-     Infus.        3.4           2.5        Amor-     After.         See   under  heading   NICKEL, 

ens,   and   gives  much 
water.       Decomposed 

emerald 
green,  and 

ous. 

ish                                                          phous                          etc. 

white. 

by  HC1  without  gela- 

sometimes 

tinizing. 

yellowish. 

. 

Soluble       in       heated 

Emerald- 

Vitre- 

Paler     Infus.         3            2.6        Amor-    After.         See  under   heading   NICKEL, 

dilute  HC1,  with  effer- 

green. 

ous, 

than                                                   phous                         etc. 

vescence.      Gives    in 

trans- 

color. 

closed   tube    a    large 

parent 

amount  of  water,  and 

to 

blackens   and    leaves 

trans- 

grayish-black     mag- 

lucent. 

netic  residue. 

Yields           sulphurous 

Light 

Metal- 

Light    ^Easily      3.5-4         4.6           I. 

See  under  heading   NICKEL, 

fumes    in     the    open 

bronze- 

lic. 

bronze-                                                                                             C(;Ci 

tube. 

yellow. 

brown. 

t 

X 

119 


NAME. 


COMP.  AND 
PERCENTAGE 
OF  IMPORTANT 
CONSTITUENT. 


SPECIFIC 


GENERAL  CHARACTERS  AND  ASSOCIATIONS. 


NICKEL  AND  ITS  COMPOUNDS.— Continued. 

NiS. 


BEFORE  BLOWPIPE. 


Millerite 
(Capil- 
lary 

Pyrites). 
(Nickel 
Blende.) 

Nickel- 
iferous 
Iron 
Pyrites. 

Ullman- 
nite. 


Nickel 
Glance 
(Gers- 
dorffite). 


Usually  in  capillary  needle-like  crystallizations.     Sometimes  like 
wool.     Fibrous;  also  in  fibrous  crusts.     Brittle,  capillary  crystals 
Nickel,  elastic. 

64.6^.  Found  with  calcite,  dolomite,  fluorite  and  ankerite  in  cavities  in 
hematite,  and  also  with  pyrrhotite.  Also  found  with  niccolite, 
nickeliferous  iron  pyrites,  chalcopyrite,  etc. 


Roasted  mineral  reacts  for  nickel  as 
above.  On  charcoal  in  R.  F. 
roasted  mineral  gives  a  coherent 
mass,  which  is  attractable  by  the 
magnet. 


(See  Iron  Ores  and  above.)  This  frequently  contains  from  ig  to  as  much  as  556  of  nickel,  and  when  it  does  is  a  valuable 
Ont.,  etc.  See  above.  The  mines  of  this  district  are  in  Huronian  rocks  (gneiss  and  red  quartz  syenite),  and  yield, 
and  the  rare  mineral  sperrylite  (arsenide  of  platinum),  q.  v. 


NiSbS. 

Nickel. 

_  27.8*. 

Antimony, 

57*. 

NiSAs. 

Nickel, 

35-4*- 
Arsenic, 

45-3X- 


Brittle  and  cubic  cleavage.     Fracture  uneven. 


Afterlong  heating  becomes  magnetic. 
Easily  fusible,  and  reacts  for  anti- 
mony, arsenic,  and  nickel.  On  char- 
coal fuses  to  globules,  boils  and 
coats  coal  white. 


Brittle,  with  uneven  fracture.    Nickel  often  replaced  by  iron  or  by     In  a  closed  tube  decrepitates  violently 
cobalt  to  considerable  extent.  and   gives    yellowish-brown   subli- 

mate.    On   charcoal   gives   arsenic 
reaction. 


120 


CHARACTERS. 

TREATMENT  WITH  ACIDS,  ETC. 


COLOR. 


LUSTRE.        STREAK 


HARD- 

NESS. 


CRYS 


MAGNETIC 


Gives    no    sulphur    in     Brass-yel-         Metal-        Bright      Easily        3.5  5.6  III.       After.         See    under  heading  NICKEL, 

closed   tube;    in   open      low  inclin-       lie, often      green-  etc- 

tube,  sulphurous      ing  to  gray  iri-      ':*   , 

fumes.  bronze-  des- 

yellow.  cent 

tarnish. 

ore.     Magnetic  iron  pyrites  (pyrrhotite)  especially  is  frequently  nickeliferous— Sudbury,     After.         See    under  heading  NICKEL, 
in  addition  to  pyrrhotite,  considerable  quantities  of  chalcopyrite  (copper  from  \%  to  4^),  etc. 


I.         After.         See  under  heading    NICKEL, 
etc. 


HC1    has    little   effect,     Steel-gray         Metal-        Gray- 

3 

5.5 

6.3 

I. 

but  nitric  acid  or  aqua      to  silver-            lie.             ish 

regia  dissolves  it,  with      white. 

black. 

separation  of  sulphur. 

Dilute    nitric   solution.     Silver-white     Metal-        Gray-      Easily 
with   chloride   of   ba-      to  steel-             lie.             black. 

5-5 

6 

I. 

After.         See  under  heading 
etc. 

Hum      added,      gives      gray  and 

heavy          precipitate.       grayish 

Aqua    regia    solution      black. 

same  as  copper  nickel. 

• 

. 

- 

NAME. 


COMP.  AND 

PERCENTAGE 
OF  IMPORTANT 
CONSTITUENT. 


GENERAL  CHARACTERS  AND  ASSOCIATIONS. 


NICKEL  AND  ITS  COMPOUNDS.-Continued. 


SPECIFIC 


BEFORE   BLOWPIPE. 


Nickel 
Ochre 
(Nickel 
Ar- 
senic). 
(Anna- 
bergite.) 


Nitre 
(Com- 
mon 
Salt- 
petre). 


Ni3As2Oe 


Nickel. 

29-  4*. 
Arsenic, 

26.6*. 

KN03. 


Soft,  earthy,  and  apple-green  in  color.  Fracture  uneven  or 
earthy.  With  soda  on  charcoal  easily  reduced  to  small,  brilliant 
metallic  particles,  which  are  highly  magnetic.  Probably  due  to 
decomposition  of  niccolite,  etc. 


Potassium  nitrate  or  potash  nitre.  Brittle,  with  uneven  fracture. 
Occurs  usually  as  needle-form  crystals  and  crusts  on  surface  of 
earth,  rocks,  and  in  caves,  etc.  Spain,  Egypt,  Persia,  and  large 
quantities  from  India. 


On  charcoal  fuses  in  R.  F.  with  emis- 
sion of  arsenical  vapor  to  blackish- 
gray  globule,  which  reacts  for 
nickel  with  borax.  Always  con- 
tains a  little  cobalt,  which  will 
usually  give  a  blue  bead  with 
borax. 

On  charcoal  deflagrates  strongly  and 
detonates  with  combustible  sub- 
stances. Fused  on  platinum  wire 
colors  flame  violet. 


Variety,       NaNO3. 
Chile 
salt- 
petre. 


Sodium  nitrate  or  soda  nitre.  Somewhat  sectile.  Deliquescent. 
Taste  cooling.  Double  refraction  in  crystals.  Occurs  granular 
or  massive,  and  forms  beds  (caliche)  in  the  Pampa  de  Tamarugal 
and  elsewhere  in  Chile,  but  is  found  also  in  small  quantities  in 
Nevada  and  California.  Usually  associated  with  large  quanti- 
ties of  common  salt,  gypsum,  and  other  impurities.  Iodine  is 
usually  present  in  minute  quantities,  nevertheless  a  very  large 
proportion  of  the  supply  of  commerce  is  drawn  from  this  source. 
See  Min.  Ind.,  Vol.  II.  345. 

122 


Deflagrates  less  violently  than  potash 
nitre,  causing  yellow  light.  Colors 
flame  intensely  yellow.  (Sodium.) 


CHARACTERS. 

TREATMENT  WITH  ACIDS.ETC. 


color.  Excess  of  am- 
monia colors  this  sap- 
phire-blue. 


Easily  soluble  in  wa- 
ter. In  solution  bi- 
chloride of  platinum 
produces  a  yellow 
crystalline  precipi- 
tate, especially  if 
stirred  with  a  glass 
rod  fora  few  minutes. 
Not  altered  by  expos- 
ure. Taste  saline  and 
cooling. 

Dissolves  in  three 
parts  of  water  at  60 
F.  Is  strongly  deli- 
quescent. Bichloride 
of  platinum  produces 
no  precipitate,  thus 
distinguishing  it  from 
potassium  nitrate 


CRYS         MAGNETIC 

COLOR. 

LUSTRB. 

STREAK 

FUSI- 
BILITY. 

HARD- 
NESS. 

SP.  GR. 

7*"-'"-       OR™                                USES. 

ZATION.          HEAT,NG> 

Apple- 

Earthy. 

Green- 

Easily 

Soft. 

V.        After.         See  under  heading    NICKEL, 

green. 

ish 
white. 

etc. 

White. 

Vitre- 

White 

Easily 

2 

2 

IV.                           Nitre  is  largely  employed  in 

ous, 

the     manufacture    of     gun- 

sub- 

powder  and  nitric  acid.     It 

trans- 

is also  used  in  medicine,  in 

parent. 

metallurgy,  and   in  chemis- 

try, as  a  powerful  oxidizing 

agent,  etc.;  to  a  certain  ex- 

tent    for    pyrotechnic    pur- 

• 

poses  and  fulminating  pow- 

ders. 

White,  gray 

Vitre- 

Whit- 

Easily 

1.5-2 

2.25 

III.                           This  is  used  to  a  certain  ex- 

yellowish, 

ous, 

ish, 

tent  in  the  manufacture  of 

orange, 

trans- 

or 

gunpowder,  for  which  pur- 

reddish 

parent 

paler 

pose  it  must  be  first  converted  into  nitre  (nitrate 

brown, 

to  sub- 

than 

of  potash),  and  also  in  the  manufacture  of  nitric 

and  lemon- 
yellow. 

trans- 
lucent. 

color. 

acid,  etc.      There    is    a    very    large    and    steady 
demand  for  Chile  saltpetre  for  use  in  the   prepa- 

ration   of    fertilizers    throughout    Europe,  which 

•• 

purpose  consumes  most  of  the  production. 

!_-!-•               •       '           •           —        •  •  •  —         —  '  -  -          * 

NAME. 


COMP.  AND 

PERCENTAGE 
OF  IMPORTANT 
CONSTITUENT. 


Obsidian      Variable. 
(Vol- 
canic 
glass). 


GENERAL  CHARACTERS  AND  ASSOCIATIONS. 


All  the  varieties  are  amorphous,  volcanic  products,  and  are  not 
homogeneous.  True  obsidian  is  characterized  by  intense  vitre- 
ous lustre,  and  contains  about  "]Q%  to  75^  silica,  and  has  essen- 
tially the  same  constitution  as  rhyolite. 

Occurs  in  connection  with  trachytic  and  more  especially  rhyolitic 
outflows.  Sometimes  occurs  as  independent  sheets  or  dikes,  but 
more  often  on  the  surface  of  crystallized  lava-sheets  or  on  the 
outer  portions  of  dikes.  (Kemp.) 

Variety:  Pumice.  This  is  finely  scoriaceous  with  linear  cells, 
and  contains  "jo%  to  78^  of  silica.  (Dana.)  It  is  characterized 
by  a  vesicular  froth-like  structure.  Pumice  is  associated  with 
obsidian. 


SPECIFIC 


Opal.  SiOs.wHjO.       Composed  of  silica  like  quartz,  but  the  true  nature  of  the  opal 

condition  of  silica  is  not  very  clearly  understood,  but  is  believed 
Water   .  to  be  one  of   lower  degrees  of   hardness  and  specific  gravity, 

variable,  Small  quantities  of  iron  oxide,  alumina,  lime,  magnesia,  and  the 

and  some-         alkalies  are  often  present,  as  well  as  quartz.     Exhibits  rich  play 
times  of  internal  reflections  and  opalescence,  the  colors  often  blending 

regarded  and  changing  according  to  the  direction  in  which  the  stone  is 

as  non-  held.     It  differs  from  quartz  in  its  lustre  and  in  the  total  absence 

essential.  of  crystalline   structure.     It  occurs   massive,   sometimes   small 

•  reniform,   stalactitic,   or  large   tuberose.     (Dana.)     It   is   found 
usually  in   cavities  or  fissures  and   seams   in    igneous  rocks — 
,„  •  usually  trachyte  and  porphyry — also  in  some  metallic  veins.     It 

is  sometimes  found  imbedded  like  flint  in  limestone  or  in  argilla- 
ceous beds.  Widely  distributed.  Fine  specimens  found  in  Hun- 
gary, Moravia,  Silesia,  Saxony,  Honduras,  etc.  The  so-called 
fire  opal  of  Mexico  is  widely  distributed  throughout  Mexico. 


124 


BEFORE  BLOWPIPE. 


Fuses  with  swelling  up,  at  3.5-4,  to  a 
vesicular  white  glass  or  enamel. 


Infusible,  but  becomes  opaque.  Some 
varieties  containing  iron  oxide  turn 
red.  With  soda  fuses  with  effer- 
vescence to  a  clear  glass. 


"* 

CHARACTERS. 

COLOR. 

LUSTRE. 

STREAK 

Fusi- 

BILITY. 

HARD- 
NESS. 

SP.  GR. 

CRYS- 

TALLl- 

MAGNETIC 
BEFORE                                  USES. 

OR  AFTER 

TREATMENT  WITH  ACIDS,  ETC. 

HEATING. 

Various, 

Intense 

3-5-4 

6 

2.2-2.8 

Amor- 

Pumice   is  used  as  a  powder 

gray,  dull 

vitre- 

phous 

for   polishing  ivory,   wood, 

greenish, 

ous. 

marble,  metals,  glass,  skins, 

purplish  to 

parchment,  etc. 

red,  brown, 

' 

. 

and  black. 

Soluble  in  hydrofluoric 
acid  rather  more  read- 
ily than  quartz.   Most- 
ly soluble   in   caustic 
potassa.         Hydrated 
silica    is    precipitated 

Colorless, 
milky- 
white,  yel- 
low, brown, 
red,  bluish 
green,  and 

Vitre- 
ous, 
subvit- 
reous, 
resin- 
ous, 

White 

Infus. 

5-5-6.5 

2-2.3 

Amor- 
phous 

When     displaying     brilliant 
and   changing    colors    used 
as  a  gem. 

by    addition    of    suf- 

dark gray- 

some- 

^gs======s=ss*sa^ 

ficient      chloride       of 

ish  green. 

times 

ff^^~  *0r  "'  ^^^^. 

ammonia. 

pearly. 

V   lifci*        THe        ^\ 

Trans- 

V               ^RS]"TV    • 

parent 

\^          OF               / 

to 

^^^JOpO  OKJltk    ^^^ 

nearly 

^^teasSSs***^ 

opaque. 

125 


NAME. 


COMP.  AND 
PERCENTAGE 
OF  IMPORTANT 
CONSTITUENT. 


GENERAL  CHARACTERS  AND  ASSOCIATIONS. 


BEFORE  BLOWPIPE. 


PHOSPHATE  ROCK. 

Mineral  variety,  apatite,  which  see.  Common  variety  is  often  probably  replacement  of  CaCO3  by  phosphate  of  lime;  also 
Floridite,  etc.)  or  as  water-worn  fragments,  probably  derived  from  this  material,  or  sometimes  as  concretionary  masses  (phos- 
nodules,  and  furnish  a  large  portion  of  the  commercial  supply.  The  substance  examined  for  phosphorus  is  mixed  with  soda,  as 
dropped  into  it.  Then  the  mixed  soda  and  substance  is  added  so  as  to  cover  the  magnesium.  Heat  to  full  fusion  the  contents  of 
characteristic  odor  of  hydrogen  phosphide  is  evolved.  (Do  not  have  too  much  water  in  vessel,  and  see  that  end  of  tube  is  broken.) 
to  nitric  acid  solution.  An  abundant  bright  yellow  precipitate  (phosphomolybdate  of  ammonium)  indicates  character  of  the 
is,  chiefly  in  the  preparation  of  commercial  fertilizers,  and  to  a  very  much  smaller  extent  in  the  manufacture  of  phosphorus  Jor 
converted  into  soluble  phosphate,  or  superphosphate,  by  being  ground  up  and  mixed  -with  sulphuric  acid  before  it  is  available  as  a 
from  certain  impurities,  such  as  iron  oxide,  alumina,  etc.  Most  of  the  Florida  rock  contains  from  6o#  to  8o«g  of  lime  phosphate.  (See 


PLATI-      Pt  (Ir,  Usually   in    flattened   or    angular     grains,    or   irregular    masses. 

NUM.         Rh,  Pd,  Sometimes    slightly   magnetic,  malleable,  and  ductile.     Usually 

Fe).  alloyed  with  iron,  rhodium,  iridium,  osmium,  and  copper.     Prin- 

Native.  cipal  supply  obtained  from  placer  deposits. 

Pt  =  from  The  commonly  associated  minerals  in  such  alluvial  deposits  are, 
50%  to  86#.  besides  quartzose  pebbles  and  sand,  magnetic  iron  sand,  gold, 
iridosmine,  topaz,  epidote,  chromite,  garnet,  and  occasionally 
zircon,  ilmenite,  serpentine,  chrysolite,  peridote,  diamond,  etc., 
Palladium  is  also  rarely  found  in  such  deposits.  It  is  rarely 
found  in  situ,  but  has  been  reported  to  have  been  so  found 
in  a  ferruginous  feldspathic  rock  with  iridosmine  in  New  South 
Wales;  also  in  grains  in  auriferous  veins  in  Brazil,  and  oc- 
casionally in  Russia. 


Infusible  except  before  oxyhydrogen 
blowpipe. 


126 


CHARACTERS. 

TREATMENT  WITH  ACIDS,  ETC. 


COLOR. 


LUSTRE.       STREAK 


FUSI- 
BILITY. 


HARD- 
NESS. 


SP.  GR. 


CRYS- 
TALLI- 
ZATION. 


MAGNETIC 
BEFORE 

OR  AFTER 

HEATING. 


USES. 


includes  fossil  bones,  fossil  excrements  (coprolites),  etc.  Occurs  massive  or  in  irregular  superficial  beds  (hard  rock  phosphate — 
phorite)  in  river-beds,  and  usually  in  stratified  marly  sediments.  Carolinas,  Florida,  etc.  These  are  referred  to  as  phosphate 
for  sulphur  (3  soda,  i  substance).  A  thin  glass  tube  closed  at  one  end  has  a  piece  of  magnesium  wire  or  ribbon  one-half  inch  long 
the  tube  until  the  glass  is  attacked.  While  still  red  plunge  under  water  in  a  small  vessel,  and  immediately  apply  the  nose.  The 
The  above  test  is  not  delicate  enough  for  minute  quantities,  as  in  Bessemer  iron  ores.  Best  test  is  to  add  molybdate  of  ammonium 

specimen. USES. — All  the   -varieties — hard  rock,   soft  rock,  land  pebble,  and  river  pebble — are  used  for  the  same  purposes,  that 

making  matches,  etc.  Very  large  deposits  in  the  southeastern  United  States  furnish  great  quantities  of  this  material,  -which  must  be 
fertilizer.  To  be  commercially  valuable  the  rock  or  pebble  should  contain  upwards  of  50^  of  phosphate  of  lime  and  be  reasonably  free 
Apatite.) 


Soluble 
regia. 


only 


aqua 


Steel-gray 
to  whitish, 
rarely 
black. 


Metal- 
lic. 


Light 
gray. 
Like 
color. 


Infus.      4-4.5       16-19 


I. 


After, 
slightly. 


A  great  part  of  the  platinum 
produced  is  made  into  va- 
rious chemical  utensils,  such 
as  crucibles,  wire,  etc.  To 
the  chemist  it  is  an  invalu- 
able metal.  It  is  also  em- 

ployed    by    balance-makers 

for  weights,  etc.,  to  a  small  extent  for 
philosophical  and  surgical  instruments, 
and  in  dentistry.  Very  considerable 
quantities  of  it  are  used  in  electrical 
appliances.  Somewhat  used  in  jewelry, 
in  photography,  in  the  manufacture 
of  non-magnetic  watches,  for  coating 
copper  and  brass,  giving  a  steel-lustre 
to  porcelain,  and  for  other  purposes. 


127 


NAME. 


COMP.  AND 

PERCENTAGE 
of  IMPORTANT 
CONSTITUENT. 


Sperry-        PtAs,. 
lite. 


GENERAL  CHARACTERS  AND  ASSOCIATIONS. 


SPECIFIC 


BEFORE  BLOWPIPE. 


Brittle.     Occurs  in  minute  crystals  or  as  scales.     In  nickeliferous     Decrepitates  slightly    When  dropped 


iron  sulphide  (pyrrhotite)  or  associated  with  pyrite,  chalcopyrite, 
cassiterite,  and  as  a  loose  material  in  small  pockets  in  the  de- 
composed ore,  near  Sudbury,  Ont.  (See  Nickel  ores.) 


on  red  hot-  platinum-foil  instantly 
melts.  Gives  off  inodorless  white 
fumes  of  arsenic,  and  porous  ex- 
crescences which  resemble  it  in 
color  are  formed  on  the  foil. 


Pyrox- 
ene 

(Augite). 
Common 
rock 

constitu- 
ent (of 
eruptive 
rocks  es- 
pecially). 


Variable.  Much  the  same  composition  as  hornblende,  which  it  closely  re- 
sembles. Sometimes  fibrous.  Chief  varieties  are:  («)  white 
augite;  (6)  green  augite;  and  (c)  hypersthene,  diallage,  bronzite, 
etc.  Massive  and  disseminated. 

Common  in  crystalline  limestones  and  dolomite,  in  serpentine  and 
in  volcanic  rocks.  Occurs  less  abundantly  in  granites  and  meta- 
morphic  rocks.  Sometimes,  however,  forms  large  veins  or 
beds,  or  interbedded  masses,  especially  in  the  older  and  highly 
metamorphosed  rocks. 


Light-colored  varieties  fuse  to  a 
white  glass,  while  the  darker  va- 
rieties give  a  black  glass. 


138 


CHARACTERS. 


TREATMENT  WITH  ACIDS,  ETC. 


COLOR. 


LUSTRE.        STREAK 


«£»- 


CRYS-       MAGNETIC 
GR.       TALLI-          ^K  °RE 
ZATION-       HEATING. 


USES. 


In  open  tube  gives  ar-     Tin-white.        Bril-            Black      As  de-         6-7           10.6           I. 
senic  sublimate.   Does                                   liant,                          scribed 

See    under    heading   PLATI- 
NUM, etc. 

not     fuse     if     slowly                                   metal- 

roasted,  but  if  rapidly                                   lie. 

heated     melts     easily 

after    part    of    its    ar- 

senic has  been  driven 

off.      In    closed     tube 

unchanged. 

Most  varieties  are  in-     All  colors,         Vitre-         White 

2-5 

5-5 

3-5 

V.         Iron  va- 

soluble  in  acids.                 usually               ous,  in-      to 

-   rieties 

black,                 clining       gray 

after. 

green,  and         to                 and 

greenish-           resin-         gray- 

black,                 ous              ish 

and              green. 

pearly. 

'• 

xt 

NAME. 


Ruby. 


Rutile. 


COMP.  AND 

PERCENTAGE 
OF  IMPORTANT 
CONSTITUENT. 

A1203. 

Oxygen, 

47- 1*- 
Alumina, 


TiOs. 

Titanic 
acid,  with 
usually  a 
little  iron. 

Ti  =  6c#. 


GENERAL  CHARACTERS  AND  ASSOCIATIONS. 


The  gems  ruby  and  sapphire  are  varieties  of  corundum,  q.  v. 
They  are  simply  the  purer  kinds  of  fine  colors,  which  are  trans- 
parent to  translucent,  and  are  useful  as  gems.  The  well-known 
red  color  of  ruby  is  its  distinguishing  characteristic.  Usually 
occurs  in  place  in  crystalline  limestone,  also  in  gneiss,  granite, 
mica  slate,  chlorite  slate,  etc.,  or  in  the  soil  derived  from  their 
decomposition,  and  in  what  is  known  as  gem-bearing  gravel. 
The  best  rubies  come  from  Upper  Burma,  north  of  Mandalay. 

The  associated  minerals  are  of  great  variety,  and  usually  include 
some  species  of  the  chlorite  group.  Differs  from  sapphire  only 
in  its  color. 


Somewhat  resembles  tin  ore,  q.  v. 

Frequently  met  with  as  a  rock  constituent  in  granite,  gneiss,  mica 
slate,  and  syenitic  rocks,  and  sometimes  in  granular  limestones 
and  dolomite;  frequently  as  secondary  product  in  many  slates. 
Sometimes  found  as  grains  or  fragments  in  auriferous  and  other 
sands.  Often  associated  with  hematite,  tremolite,  chalcopyrite, 
tourmaline,  etc. 


Sap-              AlijOs.  A  variety  of  corundum,  q.  v.     Quite  widely  distributed.     Found 

phire.  associated  with  ruby  in  the  Himalaya  Mountains.     Also  found 

Oxygen,  in  Ceylon,  in  the   Rocky  Mountains,  and  in  California.     Some- 

47. i#.  times  found  in  diamond  gravels  in  New  South  Wales.     Compare 

Alumina,  ruby  (q.  v.),  of  which  it  has  the  same  composition  and  much  re- 

52.9^,  sembles,  excepting  in  the  matter  of  color. 


130 


SPECIFIC 


BEFORE  BLOWPIPE. 


Unaltered.  Dissolves  slowly  in 
borax  and  salt  of  phosphorus  to  a 
clear  glass,  which  is  colorless  when 
free  from  iron.  It  is  not  acted 
upon  by  soda. 


Alone  infusible,  but  with  salt  of  phos- 
phorus gives  a  hyacinth-red  or 
colorless  bead, which  becomes  violet 
on  cooling,  but  brownish  red  if  iron 
is  present,  as  is  usually  the  case. 
Violet  color  best  produced  by  re- 
ducing bead  on  charcoal  with  me- 
tallic tin.  Distinguished  from  tin 
ore  by  not  affording  tin  with  soda. 

Unaltered.  Dissolves  slowly  in  borax 
and  salt  of  phosphorus  to  a  clear 
glass,  which  is  colorless  when  free 
from  iron.  It  is  not  acted  upon  by 
soda. 


CHARACTERS. 
TREATMENT  WITH  ACIDS.ETC. 

COLOR.             LUSTRE. 

__  

(*               MAGNETIC 
STREAK        FuSN         HARD-        <•     r           TA£L»           BEFORE 

-™.             NES,                                         —  .          CRATER 

USES. 

Unacted  upon  by  acids,     Red.                    Vitre-         Un- 
but     converted      into                                   ous.             col- 
a    soluble    compound                                  Trans-        ored. 
when    fused  with  po-                                   parent 
tassium  bisulphate.                                      to 
trans- 

Infus. 

9 

3-9-4-I 

III. 

The  most  highly  prized  of 
all  gems. 

Insoluble       in       acids 
alone,  but  fused  with 
soda    or    with    bisul- 
phate of  potash,  dis- 
solved    in     HC1    and 
boiled    with    tin,    the 

lucent. 

Red,  red-           Ada- 
brown,              man- 
yellow,              tine, 
black.                metal- 
lic. 

Pale 
brown 

Infus. 

6-5 

4.2 

When 
ferrif- 
erous, 
slightly 
after. 

Rutile  is  employed  for  paint- 
ing on  porcelain,  and  quite 
largely  for  giving  the  re- 
quisite shade  of  color  and 
enamel  appearance  to  arti- 
ficial teeth.  Some  kinds 

II. 

solution  becomes  vio- 
let (titanic  acid). 

make  fine  though  nearly 
opaque  gems. 

Unacted  upon  by  acids,     Blue.                  Vitre-         Un- 
but     converted      into                                 ous.             col- 
a    soluble    compound                                 Trans*        ored. 
when   fused    with   po-                                   parent 
tassium  bisulphate.                                      to 

Infus. 

9 

3-  9-4-  1 

III. 

The  purer  kinds  of  fine  color 
valuable  as  gems. 

trans- 

lucent. 

131 

NAME. 


Silica 
(Quartz). 
Most 
common 
vein 
stone 
and  rock 
con- 
stituent. 


COMP.  AND 

PERCENTAGE 
OF  IMPORTANT 
CONSTITUENT. 

SiO,. 


SPECIFIC 


GENERAL  CHARACTERS  AND  ASSOCIATIONS. 


Fracture  conchoidal  to  subconchoidal,  and  uneven  to  splintery. 
Brittle  to  tough.  Rock  crystal,  amethyst,  chalcedony,  agate, 
banded  onyx,  jasper,  flint,  silicious  sinter,  petrified  (agatized  or 
jasperized)  wood,  etc.,  are  varieties.  Most  sandstones  are 
almost  entirely  made  up  of  an  aggregation  of  small  rounded 
grains  of  quartz,  while  it  enters  very  largely  into  the  composi- 
tion of  most  other  rocks;  e.g.,  common  granite  is  composed  of 
the  three  minerals  quartz,  feldspar,  and  mica. 

Note. — The  so-called  Mexican  onyx  is  not  true  onyx,  but  is  calcite 
usually  more  or  less  impure.  (See  Calcite.) 

The  most  common  of  all  rock  constituents,  and  is  abundantly  met 
with  as  such  and  as  a  vein  stone. 


BEFORE  BLOWPIPE. 


Infusible  and  unaltered  alone.  With 
small  quantity  of  soda  fuses,  owing 
to  the  liberation  of  CO2,  or  dis- 
solves with  effervescence  to  a  clear 
glass  (when  pure).  Unacted  on  by 
salt  of  phosphorus,  and  with  borax 
dissolves  slowly  to  a  clear  glass. 


SILVER  AND  ITS  COMPOUNDS. 

Silver  compounds  when  fused  with  soda  on  charcoal  yield  a  hard,  white,  malleable  button,  usually  without  any  incrustation 
with  volatile  and  easily  oxidizable  metals,  it  may  be  separated  by  heating  on  charcoal  in  O.  F.,  but  if  associated  with  large 
white  precipitate  of  AgCl,  which  is  insoluble  in  boiling  nitric  acid,  but  readily  soluble  in  ammonia.  The  color  of  the  precipitate 
plate,  jewelry,  and  ornamental  objects,  and  as  a  money  metal.  It  is  also  largely  used  in  photography,  for  numerous  chemical  preparations, 


Native.         Ag. 


Eminently  sectile,  ductile,  and  malleable.  Sometimes  fibrous 
("  wire  "  silver),  but  often  massive  or  in  thin  sheets  or  films 
associated  with  other  ores  of  silver.  Also  disseminated,  often 
invisibly,  along  with  other  metallic  ores. 

Sometimes  associated  with  native  copper  and  galena.  It  is  doubt- 
less often  a  secondary  product  from  the  ores  of  silver,  and  is 
found  accompanying  almost  all  the  ores  of  silver,  more  fre- 
quently the  sulphides,  sulpho-salts,  and  chlorides.  Occurs  in 
both  eruptive  and  sedimentary  rocks. 


Fuses  to  white  globule,  which  in  O.  F. 
gives  a  faint  dark-red  coating  of 
silver  oxide.  Crystallizes  on  cool- 
ing. 


132 


CHARACTERS. 
TREATMENT  WITH  ACIDS,  ETC. 

COLOR. 

LUSTRE.       STREAK 

FUSI- 
BILITY. 

—  r—      ^-T^- 

r              MAGNETIC 

"ESS"       Sp-GR-       TALL'~-        OR"™                                  USES. 
ZA™N-       SEATING. 

Unaffected    by    hydro- 
chloric or  nitric  acid. 
Soluble  only  in  hydro- 

Colorless if 
pure  and 
usually 

Vitre-          White 
ous  to          or 
greasy.        paler 

Infus. 

—  "1        1         1          L. 

7             2.6           III.                           Quartz  or  silica  has  a  number 
of    uses    in    the    industries, 
especially  in  the  pure  state. 

fluoric  acid.   Dissolves 
in  alkaline  solutions. 

whitish; 
often 
smoky,  yel- 
low, red, 
black,  and 
other 
shades  of 
color. 

Splen-         than 
dent,  to       color, 
dull. 
Trans- 
parent 
to 
opaque. 

It  is  largely  used  in  the  manufacture  of  glass,  for  which  pur- 
pose pure  quartz  sand  is  frequently  used,  though  the  massive 
mineral  when  pulverized  and  when  not  impure  is  equally  well 
adapted.     It  is  also  used  in  the  manufacture  of  pottery,  of  cer- 
tain filters,  and  for  many  other  purposes  where  silica  in  a  com- 
paratively pure  state  may  be  required,  especially  in  an  admix- 
ture with  other  substances.     When  very  pure  and  transparent, 
sometimes  used  in  the    manufacture  of   eyeglasses,  or   optical 
instruments.      Chalcedony,  jasper,  silicified  wood,  etc.,  are  often 
carved  into  ornamental  objects. 

I 

on  the  coal,  but  when  treated  for  a  long  time  with  the  reducing  flame  a   slight  dark-red  coating  is  produced.     When  associated 
quantities  of  lead  or  bismuth  it  is  best  to  subject  it  to  cupellation.     (See  Appendix.)     HC1  gives  in  a  solution  of  silver  a  heavy 

changes  to  slate-purple  by  exposure  to  light.     This   is   a  distinguishing  characteristic. USHS. — Silver  is  principally  used  for 

in  the  manufacture  of  indelible  ink,  fulminating  powder,  etc. 

See    under   heading   SILVER, 
etc. 


Soluble  in   nitric  acid.     Silver-white     Metal- 

Silver- 

Easily,          2.8         10.5                I. 

The    dilute    solution,      (often  tar-         lie. 

white 

1050°                        when 

upon  addition  of  HC1      nished, 

and 

C.                             pure. 

(or  common  salt)  gives      when  it  is 

shin- 

\T\cr 

• 

a     white    precipitate,      gray  to 

ing. 

which  becomes  violet-      black). 

gray    on  exposure    to 

light.       Copper    plate 

immersed  in  nitric  solution  is  coated! 

with  silver. 

NAME. 


COMP.  AND 

PERCENTAGE 
OF  IMPORTANT 
CONSTITUENT. 


GENERAL  CHARACTERS  AND  ASSOCIATIONS. 


SILVER  AND  ITS  COMPOUNDS.— Continued. 


Silver 
Glance, 
Argentite 
(Sulphide 
or  Sul- 
phuret 
(O.  S.)  of 
Silver). 

Brittle 
Silver 
(Steph- 
anite). 
Kindred 
anti- 
monial 
and  ar- 
senical 
ores  are: 


AgiiS.  Can  be  cut  with  a  knife  like  lead  when  massive,  but  it  is  usually 

finely  disseminated  through  the  vein  material.     This  is  probably 

Silver,  the  most  common  ore  of  silver. 

87.1^.     Occurs  abundantly  with  stephanite,  native  gold,  also  native  silver 
and  copper. 


AgeSbS4.         Brittle,  with  an  uneven  fracture.     Occurs  in  veins,  etc.,  with  other 

silver  ores. 

Silver,  Note. — A  variety  is  dyscrasite  (AgsSb),  but  its  composition  is  varia- 

68. 5g.         ble.     The  following  antimonial   and  arsenical  silver  ores  pass 

readily  one  into  another  by  almost   insensible  gradations,  and 

the  analyses  of  them  often  vary  very  widely,  owing  to  presence 

of  impurities. 


SPECIFIC 


BEFORE  BLOWPIPE. 


On  charcoal  in  O.  F.  intumesces,  gives 
off  odor  of  sulphur,  and  yields  a 
globule  of  silver. 


Gives  odor  of  sulphur,  also  fumes, 
and  coating  of  antimony,  and  yields 
a  dark  metallic  globule,  which  after 
long  blowing  is  colored  red  from 
oxidized  silver,  and  from  which 
silver  may  be  obtained  by  addition 
of  soda  and  heating  in  reducing 
flame. 


Miargy- 
rite. 


AgaS.Sb2S,. 


Silver. 


36.9*- 


Brittle,  with  uneven  fracture.     Contains  less  silver  than  some  of 

the  kindred  ores. 
Occurs  with  the  other  ores  of  silver. 


134 


Fuses  on  charcoal  quietly  to  a  gray 
bead,  with  emission  of  sulphur  and 
antimony  fumes.  If  this  bead  is 
treated  for  some  time  in  O.  F.  a 
bright  globule  of  silver  is  obtained. 


........  .....j 



;  ,  .  ,.  ., 

1  1 

L          , 

CHARACTERS. 
COLOR. 

LUSTRE. 

STREAK 

FUSI- 
BILITY. 

HARD- 
NESS. 

SP.  GR. 

CRYS- 
TALLI- 

MAGNETIC 

BEFORE 
OR  AFTER 

USES. 

TREATMENT  WITH  ACIDS,ETC. 

ZATION. 

i-w»m-JT_ni  -.-_nr- 

HEATING. 

As  above  under  native     Blackish 

Metal- 

Shin- 

i-5 

~, 

,., 

I. 

See   under  heading   SILVER, 

silver.     In  open  tube      lead-gray. 

lic. 

ing 

etc. 

gives   off    sulphurous 

gray- 

fumes. 

black. 

Soluble  in  dilute  nitric     Iron-black, 
acid,  leaving    residue 
of  sulphur  and  oxide 
of    antimony,  copper 

Metal- 
lic. 

Iron- 
black. 

I 

2-5 

6-3 

IV. 

See   under  heading   SILVER, 
etc. 

plate  becoming  plated 

with    silver  as  above 

Heated  in  closed  tube  fuses  with  de- 

crepitation  and   gives  slight  subli- 

mate of  sulphide  of  antimony  after 

long  heating. 

Decomposed   by  nitric     Iron-black 

Metallic 

Red- 

Easily 

2-2.  5 

5-2 

V. 

See   under   heading   SILVER, 

acid,  with   separation      to  steel- 

—  ada- 

dish. 

etc. 

of  sulphur   and    anti-      gray.     In 

man- 

mony   trioxide.      De-      splinters 

tine, 

crepitates     in     closed      blood-red. 

nearly 

tube  and   yields   anti- 

opaque 

mony    sublimate.      In 

open  tube  sulphurous 

and  antimonial  fumes. 

135 


NAME. 


COMP.  AND 
PERCENTAGE 
OF IMPORTANT 
CONSTITUENT. 


GENERAL  CHARACTERS  AND  ASSOCIATIONS. 


SILVER  AND  ITS  COMPOUNDS.— Continued. 


Dark-red 
Silver 
Ore 

(Pyrar- 
gyrite). 

Light- 
red  Sil- 
ver Ore 
(Prous- 
tite). 


Polyba- 
site. 


Stro- 
meyer- 
ite 

(Silver- 
copper 
Glance). 


SPECIFIC 


BEFORE  BLOWPIPE. 


AgaSbSs.         Brittle  with  uneven  or  conchoidal  fracture.  On  charcoal  fuses  with  spirting  to  a 

Occurs  with  the  other  ores  of  silver,  and  principally  with  calcite,  globule,   and   gives   a  white  subli- 

Silver,                 native  arsenic,  galena,  etc.  mate  of  antimony  trioxide. 

59-  9*- 


Ag.AsS,. 

Silver, 

65-4*. 


Ag»SbS«. 

Silver, 

75-6*. 


AgaS  + 
Cu2S. 

Silver, 

53-1*. 


Like  above,  except  that  Sb  is  replaced  by  arsenic. 
Found  with  the  other  ores  of  silver,  especially  pyrargyrite,  cerar- 
gyrite,  native  silver,  and  gold. 


On  charcoal  gives  garlic  odor  of  ar- 
senic and  sulphur. 


Uneven  fracture.  Copper  is  often  present.  Arsenic  often  re- 
places the  antimony.  Otherwise  the  formula  remains  the  same 
(Mollie  Gibson  mine,  etc.,  Colorado).  A  somewhat  related  ore 
is  freieslebenite,  (PbAg2)6Sb4Sii,  containing  from  30*  to  50*  of 
lead  and  from  a  trace  to  27%  of  silver. 


Steel-gray    argentiferous    copper    sulphide.       Fracture     subcon- 

choidal. 
Usually  found  associated  with  chalcopyrite  and  galena. 


136 


Fuses  with  spirting  to  a  globule. 
Gives  off  sulphur,  sometimes  ar- 
senic, and  coats  the  coal  white. 
Arsenical  variety  gives  off  charac- 
teristic garlic  odor  of  arsenic. 

Fuses  and  gives  in  open  tube  an  odor 
of  sulphur.  Silver  globule  yielded 
only  by  cupellation  with  lead. 


MAGNETIC 


CHARACTERS. 

COLOR. 

LUSTRE.       STREAK 

FUSI- 
BILITY. 

HARD- 
NESS. 

SP.  GR. 

CRYS- 
TALLI- 

BEFORE 
OR  AFTER 

TREATMENT  WITH  ACIDS,KTC. 

ZATION. 

HEATING. 

Like  stephanite. 

Dark  red  to 

Metallic     Red. 

I 

2.5 

5.8 

_______ 
III. 

1 

black  or 

—  ada- 

grayish 

man- 

black. 

tine. 

Decomposed   by  nitric 

Cochineal- 

Ada-          Ver- 

X 

2.5 

5-5 

III. 

acid    with    separation 
of  sulphur. 

red  or 
scarlet. 

man-          m^" 

tine.           lion- 
rarely 

aurora- 

red  to 

orange- 

yellow. 

Decomposed   by  nitric 

Iron-black. 

Metal-        Black. 

Easily 

•       '     •    " 

2-3 

6.1 

IV. 

acid,  etc. 

In  thin 

lie. 

splinters 

cherry-red 

. 

Nitric    solution    gives 

Dark  steel- 

Metal-        Same 

Easily 

2.5-3 

6.25 

IV. 

with     HC1    a     heavy 

gray. 

lie.               as 

precipitate. 

color, 

but 

more 

shin- 

ing. 

1 

.    4 

nry 

USES. 


See  under  heading  SILVER, 
etc. 


See  under  heading  SILVER. 
etc. 


See  under  heading  SILVER, 
etc. 


See  under  heading  SILVER, 
etc. 


NAME. 


COMP.  AND 
PERCENTAGE 
OF  IMPORTANT 
CONSTITUENT. 


GENERAL  CHARACTERS  AND  ASSOCIATIONS. 


SILVER  AND  ITS  COMPOUNDS.— Continued. 


Horn 
Silver  or 
Silver 
Chlo- 
ride 
(Cerar- 
gyrite). 
Kindred 
and 
asso- 
ciated 
ores  are: 


AgCl. 

Silver, 

75-3X- 


Embolite, 

Ag(ClBr). 

which 

passes 

Silver,  about 

into 

64^.     Very 

variable. 

Ratio  of 

chlorine  to 

bromine 

varying  in- 

definitely. 

The  common  ore  of  Mexico  and  South  America.  Not  common, 
except  in  southern  part,  in  the  United  States.  A  very  valuable 
ore,  as  it  is  easy  of  treatment  (free-milling).  It  is  an  alteration 
product  of  the  foregoing  ores  and  owes  its  origin  in  many  cases 
probably  to  the  percolation  of  sea  or  salt  water  throughout  the 
upper  portions  of  the  veins  or  other  classes  of  deposits,  as  in 
depth  the  ores  invariably  change  into  their  original  condition  of 
sulphides.  Highly  sectile  when  very  pure,  cutting  like  hard 
wax  or  a  piece  of  horn;  hence  its  name.  Fracture  somewhat 
conchoidal.  No  cleavage.  Occurs  massive  and  waxlike,  or  as 
incrustations. 

Found  associated  with  the  other  ores  of  silver,  but  usually  for  the 
reasons  given  above,  in  the  upper  portions  of  the  veins  contain- 
ing silver  ores.  Often  associated  with  oxide  of  iron  and  other 
alteration  products.  Found  frequently  with  copper  ores,  calcite, 
barite,  etc. 

A  rare  variety  is  huantajayite  (2oNaCl  +  AgCl),  which  is  found 
near  Iquique,  Chile,  only,  however,  to  a  depth  of  20  metres. 


The   yellow   and   deep- 
quantities    of    bromine. 


Fracture  uneven,   no  cleavage,   sectile. 

green    varieties    contain    the    largest 

Abundant  in  Chile. 
Associated  with  the  other  silver  ores,  of  which  it  is  an  alteration 

product.     Also  frequently  associated  with  cerussite. 


SPECIFIC 


BEFORE   BLOWPIPE. 


Fuses  in  flame  of  candle,  emitting 
acrid  fumes  (Cl).  Malleable  and 
sectile.  On  charcoal  yields  a  glob- 
ule of  metallic  silver.  In  salt  of 
phosphorus  bead,  to  which  oxide 
of  copper  has  been  added,  and 
heated  in  O.  F.,  an  intense  azure- 
blue  color  is  imparted  to  the  flame. 


Pungent  bromine  vapors  are  emitted 
when  it  is  heated  on  charcoal,  and 
a  button  of  metallic  silver  remains. 


138 


CHARACTERS. 

f  „.       1 

HAGNETIC 

COLOR. 

LUSTRE. 

STREAK 

FUSI- 
BILITY. 

HARD- 
NESS. 

SF.  GR. 

CRYS- 
TALLI- 

BEFORE 
DR  AFTER 

USES. 

TREATMENT  WITH  ACIDS,  ETC. 

ZATION. 

ABATING. 

Soluble    in    ammonia, 

Pearl-gray, 

Resin- 

Shin-      ^ 

fery 

1-1.5 

5-5 

I. 

See   under  heading   SILVER, 

but  not  in  nitric  acid. 

whitish,  and 

ous- 

ing,         c 

sasily 

etc. 

In   closed    tube    with 

colorless; 

ada- 

trans- 

bisulphate of  potassa 

upon  expo- 

man- 

parent 

gives  off  acid  vapors. 

sure  to  light 

tine. 

to  sub- 

Fuses  to  a  pale  hya- 
cinth-red globule.  Be- 

turns into 
violet  and 

trans- 
lucent. 

comes    yellow     when 

other  tints 

cold.     A  plate  of  iron 

of  brown. 

rubbed  with  the  min- 

Passes into 

eral  becomes  silvered. 

green  and 

blue. 

Rarely 

violet-blue. 

» 

In  closed  tube  gives  off 
bromine    vapors   and 

Gray-green, 
asparagus- 

Resin- 
ous to 

Shin- 
ing. 

easily 

I-I-5 

5-4 

I. 

See    under  heading  SILVER, 
etc. 

fuses    to    an    intense 

green  to 

some- 

garnet    red     globule, 

yellow  and 

what 

which  is  yellow  when 

green-yel- 

ada- 

cold.    Soluble  in  am- 

low; b&- 

man- 

monia, but  not  as  solu- 

comes 

tine. 

ble  as  the  above. 

darker  on 

exposure. 

13 

3 

COMP.  AND 

N*MK  PERCENTAGE 

MB>          OF  IMPORTANT 

CONSTITUENT. 


GENEKAL  CHARACTERS  AND  ASSOCIATIONS. 


SILVER  AND  ITS  COMPOU1TDS.— Continued. 


Bromy-        AgBr. 
rite. 

Silver, 

57-4X- 


No  cleavage  and  fracture  uneven,  sectile.     Abundant  in  Chile. 


SPECIFIC 


BEFORE  BLOWPIPE. 


Same  as  above. 


lodyrite.      Agl. 


Perfect  cleavage.     Sectile,  plates  flexible.     Chile,  New  Mexico,     B.  B.  gives  fumes  of  iodine  and  me- 

Arizona,  Spain,  etc.  tallic  silver. 

Silver,  46*.     Same  as  above. 
Iodine,  54%. 


Argentiferous  Galena.     (See  Lead  ores.)     This  very  frequently  carries  silver,  and  is  a  very  common  ore  of  the  latter. 
Argentiferous  Cerussite.     (See  Lead  ores.)     This  very  frequently  carries  silver,  and  is  a  -very  common  ore  of  the  latter.     Results 
Argentiferous  Zinc  Blende.     (See  Zinc  ores.)     This  less  frequently  carries  silver.      Generally  associated  with  galena,  iron  and 

Argentiferous  Pyrites.    (See  Iron  and  Copper  ores.)    The  various  kinds  of  pyrites  very  frequently  carry  small  percentages  of  silver. 

140 


CHARACTERS. 


TREATMENT  WITH  ACIDS,ETC. 


COLOR. 


- 


LUSTRE.       STREAK 


FUSI- 
BILITY. 


HARD- 
NESS. 


SP.  GR. 


CRYS- 
TALLI- 
ZATION. 


MAGNETIC 

BEFORE 
OR  AFTER 

HEATING. 


USES. 


In  closed  tube  and  with 
metallic  zinc  much  the 
same  reaction  as  cer- 


Easily        2-3         5.5-6 


argyrite.     Fused  with 

ber-yellow;       man-           color. 

potassium    bisulphate 

often  grass-      tine. 

gives    off     yellowish- 

green  or 

brown     vapors     (Br). 

olive-green. 

With  difficulty  soluble 

Externally 

in  ammonia. 

little  altered 

on  ex- 

posure. 

' 

Inclosed  tubefusesand 
assumes  deep  orange 

Citron  and        Resin-        Yellow,     Easily     Soft.           5.7           III. 
sulphur-           ous  to          trans- 

See   under   heading   SILVER, 
etc. 

color,  but  is  yellow  on 

yellow  to          ada-              lucent. 

cooling.     Fused    with 

yellowish          man- 

potassium    bisulphate 

green;                tine. 

in    a    matrass    yields 

sometimes 

violet  vapors,  and  the 

brownish. 

globule  becomes  very 

dark  or  almost  black. 

usually  from  superficial 

decompositio 

n  of  above. 

copper  pyrites,  etc.,  in  s 

ilver  mines. 

See   under   heading   SILVER, 
etc. 


NAME. 


COMP.  AND 

PERCENTAGE 
OF  IMPORTANT 
CONSTITUENT. 


GENERAL  CHARACTERS  AND  ASSOCIATIONS. 


BEFORE  BLOWPIPE. 


SILVER  AND  ITS  COMPOUNDS.- Continued. 

Tetrahedrite  (Gray  Copper).     (See  Copper  ores.)     This   frequently  carries  a  large  percentage  of  silver,  but  not  often  found  in 


SULPHUR  AND   SULPHIDES. 

The  following  is  usually  sufficient  to  detect  the  presence  of  sulphur:  Mix  the  substance  suspected  to  contain  sulphur  with 
silver  (coin  or  plate),  and  a  drop  of  water  is  added.  A  yellowish  stain  on  the  silver  indicates  a  trace  of  sulphur;  larger 
sulphur.  Mixed  with  soda  as  above  and  heated  in  O.  F.  on  platinum  wire,  the  sulphides  color  the  coin  brown  to  black,  but 
and  colors  the  coin.  Sulphides,  or  substances  containing  sulphides  in  considerable  quantities,  yield  sulphur  dioxide  when  heated 
inserted  in  end  of  tube.  Usually  soluble  in  nitro-hydrochloric  or  concentrated  nitric  acid.  Some  are  extremely  difficult  to  dissolve 
upon  it,  but  these  can  usually  be  recognized  by  their  volatility,  etc.  (mercury,  arsenic,  etc.).  The  higher  sulphides  give  off  sulphur 

of  burning  sulphur. USES. —  7'he  chief  use  of  sulphur  is,  of  course,  in  the  manufacture  of  sulphuric  acid,  this  acid  being  produced  in 

lucifer-matches,  for  bleaching,  and  for  medicinal  purposes. 


Sulphur. 


S. 


Taste  is  scarcely  perceptible,  odor  when  rubbed  faintly  sulphur- 
ous. Yellow  when  pure,  but  usually  gray  or  brown  because  of 
admixture  with  earthy  substances,  clay,  bitumen,  etc.  Fracture 
conchoidal  to  uneven.  Associated  with  gypsum,  calcite,  celes- 
tite,  and  abundant  in  regions  of  present  and  ancient  volcanic 
activity.  Andes,  Sicily,  Mexico,  Yellowstone  Park,  and  almost 
world-wide  distribution. 

Found  often  near  sulphur  springs,  in  many  coal  deposits,  and  at 
other  places  where  pyrites  is  undergoing  decomposition. 


Melts  at  108°  C.  (some  varieties  at 
114°  C.)  and  at  270°  burns  with 
blue  flame,  emitting  the  suffocating 
odor  of  s.ulphurous  acid  gas,  which 
it  forms  by  combining  with  the  oxy- 
gen of  the  air. 


TELLURIUM  AND  ITS  COMPOUNDS. 

Rarely  occurs  native,  when  it  is  a  white  and  brittle  metal,  which  is  easily  fusible,  volatilizing  almost  entirely  and   tinging 
decomposing  horse-radish.     Usually  combined  with  the  other  metals  as  tellurides  of  gold,  silver,  lead,  and  bismuth,  which  see. 

in  nitric  acid.     Occurs  usually  accompanying  quartz,  pyrite,  gold,  fluor-spar,  etc. USRS. — Of  no  use  in  the  arts. 

142 


In 


CHARACTERS. 


TREATMENT  WITH  ACIDS.ETC. 


I  I   — 


COLOR. 


LUSTRE.       STREAK 


Fusr- 

BILITY. 


"JSKS. 


large  quantities.     When  argentiferous  its  color  is  usually  steel-gray,  or  lighter  than  the  ordinary  varieties. 


soda  (3  soda,  I  substance)  and  heat  on  platinum  wire  or  charcoal  in  R.  F.  The  fused  mass  is  then  crushed  on  a  clean  piece  of 
quantities  give  a  brown  or  a  black  stain.  Sulphides  such  as  pyrites,  galena,  etc.,  heated  on  charcoal  give  the  odor  of  burning 
sulphates,  gypsum,  baryta,  etc.,  so  treated  in  O.  F.,  do  not  color  the  coin;  in  R.  F.,  however,  the  sulphate  is  changed  to  sulphide 
in  open  tube.  The  sulphur  dioxide  may  be  recognized  by  its  odor,  and  by  reddening  and  sometimes  bleaching  blue  litmus  paper 
completely,  owing  to  the  deposition  of  sulphur,  which  fuses  around  the  unaltered  substance  and  prevents  any  action  of  the  acid 
when  heated  in  closed  tube.  Free  sulphur  (</.  v.)  fuses  and  sublimes,  and  on  charcoal  burns  with  a  blue  flame,  and  affords  odor 
commercial  quantities  only  from  native  sulphur  and  pyrites.  It  is  also  largely  used,  however,  in  the  manufacture  of  gunpowder  and 


Insoluble  in  water. 
Natural  and  arti- 
ficially formed  crys- 
tals are  soluble  in  di- 
sulphide  of  carbon, 
but  the  amorphous 
form  is  not.  Crystal- 
line forms  also  soluble 
in  sulphide  of  chlo- 
rine, benzine,  turpen- 
tine, etc.  Not  acted 
on  by  acids. 


Sulphur-yel- 
low, gray, 
brown,  or 
reddish  to 
greenish. 


Resin- 


Like 
color. 


Easily     1.5-2.5       2.07         IV. 


See  under  heading  SULPHUR, 
etc. 


the   flame   green.     White  coating  on   charcoal.       It   fumes   strongly,  and  in    presence   of  selenium    gives   the    peculiar   odor  of 
ooen  tube  a  white   or  grayish  sublimate  (tellurium  dioxide)  is  obtained,  which  may  be  fused  to  clear,  colorless  drops.     Soluble 


143 


NAME. 


COMP.  AND 

PERCENTAGE 
OF  IMPORTANT 
CONSTITUENT. 


GENERAL  CHARACTERS  AND  ASSOCIATIONS. 


SPECIFIC 


BEFORE  BLOWPIPE. 


At  the  same  time  a 


TIN  AND  ITS  COMPOUNDS. 

Fused  with  soda  and  borax  on  charcoal  in  R.  F.,  the  compounds  of  tin  yield  a  globule  of  the  metal. 
must  be  kept  covered  with  the  blue  R.  F.  The  coating  moistened  with  cobalt  solution  and  heated  in  the  O.  F.  assumes  a  bluish- 
with  metallic  zinc,  metallic  tin  is  thrown  down  in  the  form  of  scales,  or  as  a  gray  spongy  mass.  -  USES.  —  Tin,  as  a  metal,  has  a 
sheet  iron  (tin  plate),  etc.  It  is  largely  used  as  an  alloy,  e.g.,  with  copper,  forming  bell-metal,  in  the  manufacture  of  solders,  etc.  It  is 
is  employed  for  polishing  hard  stone  and  sharpening  fine  cutting  instruments  and  in  enamels.  The  chlorides  are  used  in  dyeing  and 
bronze-powder. 


Tin 
Stone 
(Cassi- 
terite). 
(Stream 
Tin.) 


Tin 

Pyrites 
(Stan- 
nite). 


Practically  the  only  ore.  Its  high  specific  gravity  is  very  notice- 
able;  likewise  its  hardness.  (Compare  garnet  and  rutile.)  Frac- 
ture  uneven  or  subconchoidal.  When  found  in  place  it  is  usually 
associated  with  quartz,  copper,  and  iron  pyrites,  wolframite, 
mica,  tourmaline,  apatite,  fluorite,  sphalerite,  molybdenite,  ar- 
senopyrite,  etc.  When  in  place  it  is  usually  found  in  veins  in 
granite,  quartzose  gneiss,  quartzite,  metamorphic  slate,  mica 
schist,  and  porphyry.  It  is,  however,  quite  largely  obtained 
from  placer  deposits,  when  it  is  frequently  associated  with  plati- 
num, iridosmine,  gold,  corundum,  etc. 

CujS.FeS,       Sulphide  of  tin.     "  Bell-metal  ore."     Rare.     Easily  fusible.    Mas- 
SnS2.  sive,  granular,  and  disseminated.     Cubic  cleavage,  uneven  frac- 

ture,  and   brittle.      Often  yellowis.h    from    presence   of   copper 
Tin,   27.5^.         pyrites.     Zinc  is  often  present. 

Copper,  Commonly   found    massive   and   associated   with    tin-stone    (cas- 

29.5*.         siterite),  wolframite,  also  in  quartz  with  native  bismuth,  scheel- 

ite,  pyrite,  galena,  sphalerite,  etc. 


144 


B.  B.  alone  unaltered.  With  soda  on 
coal  reduced  to  metallic  tin,  and 
gives  a  white  coating,  Requires 
long  blowing.  Hastened  by  addi- 
tion of  potassium  cyanide.  The 
globule  is  malleable,  and  reacts  for 
tin.  Sometimes  reacts  for  iron  and 
manganese.  The  fine  powder  gives 
tin  reaction  with  cobalt  nitrate. 


On  charcoal  after  long  blowing  fuses 
to  a  brittle  metallic  globule,  which 
in  O.  F.  gives  off  sulphur  and  coats 
the  coal  white  with  oxide  of  tin. 
In  open  glass  tube  gives  off  sulphur 
(forming  fumes  of  sulphurous  acid) 
and  also  forming  close  to  assay 
sublimate  of  oxide  of  tin,  which 
cannot  be  volatilized  by  heat. 


CHARACTERS. 

COLOR. 

LUSTRE. 

STREAK 

FUSI- 
BILITY. 

HARD- 
NESS. 

CRYS- 
SP.  GR.       TALLI- 

MAGNETIC 
BEFORB                                    USES. 

OR  AFTER 

TREATMENT  WITH  ACIDS,  ETC. 

HEATING. 

coating  is  formed  on  the  coal,  which  is  slightly  yellow  when  hot,  but  white  when  cold.  To  obtain  a  coating,  however,  the  assay 
green  color.  Sulphides  should  always  be  roasted.  When  a  solution  of  salts  of  tin,  acidulated  with  HC1,  is  brought  in  contact 
wide  application  in  the  industries.  It  is  employed  for  making  castings,  and  -very  extensively  for  coating  iron  and  copper  -vessels,  especially 
also  used  in  the  manufacture  of  tin-foil,  and  when  amalgamated  with  mercury  for  silvering  mirrors.  The  dioxide  {prepared  artificially) 
calico-printing.  The  bisulphide,  on  account  of  its  golden  lustre,  is  used  in  ornamental  painting,  etc.,  and  known  under  the  name  of 


Insoluble   in    acids   or 

Brown, 

Ada- 

White-    Infus. 

only    slightly    acted 

black,  and 

man- 

gray- 

upon. 

brown- 
black, 

tine  to 
dull. 

ish  to 
brown. 
Trans- 

sometimes 
red,  gray, 

Crys- 
tals 

parent 
to 

.    white,  or 

usually      opaque 

yellow. 

splen- 

dent. 

Soluble   in   nitric   acid     Steel-gray 

Metal- 

Black-     Easily 

to  a  blue  solution,  with      (when  pure)      lie. 

ish. 

separation  of  sulphur      to  brown- 

and  binoxide  of  tin. 

black. 

Sometimes 

a  bluish 

tarnish. 

6-7       6.8-7.1        II. 


4-4 


Us- 
ually 
mas- 
sive. 


See  under  heading  TIN,  etc. 


See  under  heading  Titf,  etc. 


NAMK. 


COMP.  AND 

PERCENTAGE 
OF  IMPORTANT 
CONSTITUENT. 


GENERAL  CHARACTERS  AND  ASSOCIATIONS. 


SPECIFIC 


BEFORE   BLOWPIPE. 


Topaz. 


B.  B.  Infusible.  Fused  in  closed  tube  with 
salt  cf  phosphorus  previously  fused,  etches 
the  glass  and  gives  off  silicon  fluoride. 
Some  varieties  become  yellow  or  more  often 
pink  when  heated.  Moistened  with  cobalt 
nitrate  and  ignited  assumes  a  fine  blue 
color. 


AljjSijOjsFio  Cleavage  both  perfect  and  imperfect.  Fracture  subconchoidal  to  uneven. 
Brittle.  The  colorless  varieties  resemble  diamonds,  but  are  easily  distin- 
guished from  them  in  that  they  are  of  inferior  hardness,  that  they  lack 
"fire "and  become  electric  when  heated.  The  color  of  the  deep  wine-red 
crystals  is  apt  to  fade  out  on  exposure  to  daylight,  and  the  yellow  color  of 
some  of  the  crystals  from  Brazil  is  changed  to  rose-red  by  being  heated. 
Oriental  topaz  is  yellow  corundum  and  Scotch  topaz  is  yellow  smoky  quartz, 
from  each  of  which  true  topaz  is  easily  distinguished.  Occurs  either  crystal- 
lized, in  association  with  granitic,  gneissoid,  or  talcose  rocks,  or  in  the  form 

of  rolled  pebbles  in  gravel.  The  associated  minerals  are  tourmaline,  mica,  beryl,  and  sometimes  apatite,  fluorite,  and  cas- 
siterite.  Sometimes  found  in  cavities  in  rhyolite  and  similar  volcanic  rocks.  Siberia  furnishes  the  best  stones,  but  many 
are  obtained  from  Brazil.  Also  found  in  New  South  Wales,  Tasmania,  Mexico,  and  sometimes  in  the  United  States. 

TUNGSTEN  AND  ITS  COMPOUNDS. 

Before  blowpipe  compounds  of  tungsten  impart  to  salt  of  phosphorus  bead  at  first  a  dirty-green,  then  a  blue  color  when 

phosphoric  acid  its  compounds  give  a  beautiful  blue  syrup.     Often  associated  with  tin  ores,  etc.     The  ores  are  rare. USES  —  The 

hardening  steel),  the  tungsten  imparting  to  the  steel  a  high  degree  of  hardness.      Tungstate  of  soda  has  been  employed  as  a  mordant  in 
like  alum,  can,  however,  be  used  for  the  same  purpose.      Also  used  for  hardening  plaster  of  Paris  and  in  the  manufacture  of  tungstic  acid. 


Wolfram- 
ite. 


(Fe.Mn,)  Swedish  heavy  stone.     Its  true  nature  will  be  suspected  from  its  great  weight, 

WO4.  very  dark-grayish  or  reddish-black  color,  submetallic  or  adamantine  lustre, 

and  red-brown  streak.     Tungstate  of  iron   and  manganese.      Both   massive 
Tungsten  and  crystalline.     Breaks  readily  into  angular  fragments.    Variety,  Tungstite 

trioxide  (vVO»),  which   reacts   for  tungsten   only,  and   which  occurs  in  soft,   bright 

=  76.4756.  yellow  or  yellowish-green  earthy  masses.  Due  to  decomposition  of  wolfram- 
Manganese  ite,  which,  commercially  speaking, -is  the  only  ore.  Hubnerite  is  a  nearly 
and  Iron  pure  manganese  wolframite  (MnWO4). 

very  varia-         Usually  occurs  in  quartz  veins,  sometimes  quite  massive,  sometimes  dissemi- 
ble.  nated   throughout  the  vein   material,   and  frequently   as  nests  or  bunches 

irregularly  distributed  through  the  gangue.  Very  frequently  associated  with 
cassiterite,  also  with  bismuth,  scheelite,  pyrite,  galena,  sphalerite,  etc.,  some- 
times with  gold. 


146 


Fuses  quite  easily  to  gray  and  often  crystal- 
line globule  which  is  magnetic.  With 
borax  manganese  reaction.  With  soda  on 
platinum-foil  gives  the  bluish-green  man- 
ganese reaction.  With  salt  of  phospho- 
rous gives  a  clear  reddish-yellow  glass 
when  hot,  which  is  paler  on  cooling;  in 
R.  F.  becomes  dark  red  ;  on  charcoal  with 
tin,  if  not  too  saturated,  bead  becomes 
green  on  cooling,  and  with  continued 
treatment  in  R.  F.  changes  to  reddish 
yellow.  Often  feebly  magnetic. 


CHARACTERS. 


TREATMENT  WITH  ACIDS,  ETC. 


COLOR.  LUSTRE.       STREAK 


SP.  GR. 


MAGNETIC 

«££ 
HEATING. 


Not   affected    by  acids    or     Colorless,  pale 
only  partially  affected   by      yellow,  white 
sulphuric  acid.                           bluish,  green 
ish    and    red 
dish. 

Vitreous. 
Transpa- 
rent to 
subtrans- 
lucent. 

White. 

Infusi- 
ble or 
fusible 
above 
5- 

8 

3-4- 

IV. 

The   purer   varieties  are   used   as 
gems   in   jewelry.     Owing   to  its 
perfect  cleavage,  it  is  a  poor  sub- 
stitute for  emery. 

t,      . 

cold.  If  iron  is  present  the  bead  appears  blood-red.  Best  with  tin  on  charcoal.  Characteristic  reaction  is  when  boiled  with 
chief  use  of  tungsten  ore  is  in  the  preparation  of  ff.rro-tungsten  and  tungsten  metal  for  making  tungsten  steel  (ordinarily  called  self- 
dyeing,  and  for  the  impregnation  of  vegetable  tissues,  linen,  cotton,  and  other  light  fabrics,  to  render  them  non-inflammable.  Cheaper  salts, 


Reduced  to  fine  powder  and     Black,  dark 
boiled    with    aqua    regia,       grayish  to 

Subme- 
tallic  to 

Black 
to  dark 

2-5-3 

5-5 

7.2 

V. 

Both. 

See  under  heading  TUNGSTEN,  etc. 

assumes  gradually  a  yel-      brownish 

resinous, 

reddish 

low  color.      Boiled    with      black.     Also 

adaman- 

brown, 

phosphoric    acid    gives    a       brownish 

tine. 

yellow- 

beautiful       blue        syrup       red  and  hair- 

Some- 

brown 

(tungsten).        The      blue      brown. 

times 

and 

syrup  is  changed  to  violet 

splen- 

green- 

by addition  of  nitric  acid.   ! 

dent. 

ish 

It   is   sufficiently  decomposed   by   concen- 

gray. 

trated  sulphuric  or  even  hydrochloric  acid 

to   give  a.   colorless  solution  which,  when 

treated  with  metallic  zinc,  becomes  intensely 

blue,  but  soon  bleaches  on  dilution. 

147 


»» 
.NAME. 


COM  P.  AND 
PERCENTAGE 
OF  IMPORTANT 
CONSTITUENT. 


GENERAL  CHARACTERS  AND  ASSOCIATIONS. 


TUNGSTEN  AND  ITS  COMPOUNDS.— Continued. 


Scheel- 
ite. 


CaWO4. 

Tungsten, 
63.8*. 


Tur- 
quois. 


2A12OS, 
P20S, 
5H20. 

Variable. 


Cleavage  very  distinct.  Brittle,  with  uneven  fracture.  Reniform, 
massive,  granular.  Molybdenum  is  usually  present,  replacing 
part  of  the  tungsten.  Found  usually  in  crystalline  rocks  asso- 
ciated with  tinstone,  apatite,  fluorite,  topaz,  wolframite,  molyb- 
denite, and  in  quartz  along  with  gold,  etc. 


SPECIFIC 


BEFORE  BLOWPIPE. 


A  hydrous  phosphate  of  aluminum  colored  by  presence  of  some 
compound  of  copper.  Rather  brittle,  no  cleavage.  In  thin 
seams  and  disseminated  grains.  Usually  in  trachytic  rocks,  or 
in  the  neighborhood  of  them,  as  very  thin  seams  or  small  masses 
in  the  cracks  or  joint  planes,  etc. 

In  Persia  it  is  found  not  only  in  the  brecciated  trachyte,  but  in 
the  surrounding  clay  slate. 


In  forceps  fuses  with  some  difficulty 
to  a  semi-transparent  glass.  With 
borax  the  glass  is  transparent,  but 
on  cooling  it  becomes  opaque  and 
crystalline.  With  salt  of  phosphorus 
the  glass  is  colorless  in  the  outer 
flame,  but  is  green  in  the  inner 
flame  when  hot,  and  a  fine  blue  when 
cold.  If  iron  is  present  specimen 
must  be  treated  with  tin  before  this 
effect  is  obtained. 

In  forceps  becomes  brown  and  glassy, 
but  does  not  fuse.  Colors  flame 
green.  Moistened  with  HC1  the 
color  is  at  first  blue.  With  the 
fluxes  gives  yellowish-green  beads 
when  hot,  which  are  pure  green  on 
cooling. 


148 


CHARACTERS. 

PC         MAGNETIC 

COLOR. 

LUSTRE. 

STREAK        Fus1'         HARD-       -     G          J~R  s             BEFORE                                    ., 

BILITY.             NESS.                                                                      OR  AFTER 

TREATMENT  WITH  ACIDS,  ETC. 

1 

HEATING. 

Inhydrochloric  ornitric 

Yellow,  yel- 

Vitre- 

White         5          4.5-5          6            II. 

See    under     heading     TUNG- 

acid   is    decomposed. 

lowish 

ous  to 

STEN,  etc. 

leaving  a  yellow  pow- 

white, pale 

ada- 

der which  is  soluble  in 

yellow, 

man- 

ammonia. 

brownish, 

tine. 

greenish, 

Trans- 

reddish, 

parent 

and  rarely 

to 

I 

orange- 

trans- 

: 

yellow. 

lucent. 

• 

—  MWMM 

Soluble  in  hydrochloric 

Sky-blue, 

Waxy, 

White     Infus.          6             2.6 

The  principal  use  is  in  jew- 

acid.    In  closed   tube 

bluish 

feeble. 

or 

elry.    Fossil  bones  and  teeth 

decrepitates,       yields 

green  to 

green- 

colored by  phosphate  of  irot  , 

water,       and        turns 

apple-  green 

ish. 

and     termed     odontolite,    or 

brown  or  black. 

and  green- 

Sub- 

bone      turquois,     are      fre- 

ish gray. 

trans- 

quently   cut    and     polished 

lucent 

for  the  same  purpose. 

to 

opaque 

• 

.1- 

1Q 

• 

NAME. 


Wollas- 
tonite 
(Tabular 
Spar). 
(A  vein- 
stone.) 


COMP.  AND 

PERCENTAGE 
OF  IMPORTANT 
CONSTITUENT. 

CaOiSi. 


GENERAL  CHARACTERS  AND  ASSOCIATIONS. 


A  somewhat  rare  veinstone  (in  the  same  sense  that  baryta,  calcite, 
etc.,  are  veinstones).  Brittle,  with  uneven  fracture,  but  perfect 
cleavage.  Usually  with  long  fibres  or  columnar  structure.  In 
granitic  regions,  in  granular  limestones,  and  along  with  some 
basaltic  lavas. 

Often  found  associated  with  lime  garnet,  pyroxene,  etc. 


"  SPECIFIC 


BEFORE   BLOWPIPE. 


Fuses  quietly,  but  with  difficulty,  to 
a  colorless  translucent  glass.  In 
closed  tube  no  change.  With  much 
soda  swells  up  and  becomes  in- 
fusible. 


ZINC  AND  ITS  COMPOUNDS. 

Compounds  of  zinc  with  borax  give  a  clear  glass,  which  is  milk-white  on  flaming,  or  with  more  assay  becomes  enamel-white 
is  yellow  when  hot,  but  white  when  cold.  With  soda  on  charcoal  the  ores,  even  when  containing  little  zinc,  afford  the  peculiar 
yellowish-  or  dirty-green  color  is  obtained  (either  alone  or  with  soda),  while  tin  gives  a  bluish-green  color  when  similarly 
•what  is  known  as  galvanized  iron.  Its  alloys  with  copper,  lead,  tin,  and  other  metals  are  of  great  importance',  e.g.,  with  coppei  making 


Zinc-  ZnS.  The    most    abundant    ore.     Generally   can   be    recognized   by   its 

blende  appearance.     It  is  massive,   cleavable,  coarse  to  fine  granular, 

(Spha-         Zinc,  67^.  and  compact;  also  foliated  and  fibrous,  radiated  and  botryoidal. 

lerite;  Brittle.      Fracture  conchoidal.     Sometimes  contains    iron,  man- 

Black-  ganese,  etc.     Is  frequently  argentiferous  or  auriferous.     Corn- 

jack),  mon  in  silver  mines. 

Occurs  in  rocks  of  all  ages,  in  veins,  in  contact  deposits,  or  in 
irregular  pockets  in  limestone,  etc.,  and  is  frequently  associated 
with  the  ores  of  lead,  as  well  as  those  of  copper,  iron,  silver, 
gold,  and  tin;  also  frequently  associated  with  quartz,  barite, 
fluorite,  calcite,  etc.  Widely  distributed. 

150 


With  soda  on  charcoal  gives  in  R.  F. 
a  strong  green  zinc  flame  and  a 
coating  of  oxide  of  zinc,  with  fumes 
of  sulphur.  Alone  on  charcoal 
gives  fumes  of  zinc  when  strongly 
heated.  Sometimes  phosphorescent 
when  rubbed  or  struck  with  a  stick. 


1              1               1 

CHARACTERS. 

COLOR. 

LUSTRE. 

CRYS-       MAGNETIC 
STRFAK        Fus1'          HARD-       s       -            ;-""'            BEFORE                                       TT  _. 

bTREAK         BIUTy                     s               bP.    GR.          TALLl             QR                                                                     USES. 

TREATMENT  WITH  ACIDS,  ETC. 

ZATION.          HEATJNG. 

Decomposed    by    HC1, 

White  to 

Vitre- 

White 

4-5 

4-5 

2.9 

V. 

frequently      efferves- 

whitish 

ous  to 

cing      slightly     from 

gray.      In 

pearly 

presence       of      small 

some  speci- 

on 

quantities       of       cal- 

mens  yel- 

cleav- 

cite, and  gelatinizing. 

lowish, 

age 

After     separation    of 

reddish, 

sur- 

the   silica,   carbonate 

and 

faces. 

of  ammonia  causes  a 

brownish. 

copious  separation  of 

carbonate  of  lime. 

on  cooling.     In  the  R.  F.  on  charcoal  burns  with  a  greenish-blue  flame.     Fumes  are  given  off  depositing  much  oxide, which  coating 
bluish  flame  of  burning  zinc,  and  the  oxide  is  deposited  on  the  coal.     When  this  coating  is  moistened  with  cobalt  nitrate,  a  fine 

treated. USES. — Zinc  is  extensively  employed  in  sheets  for  roofing  and  other  purposes,  and  for  coating,  as  in  the  manufacture  of 

brass,  etc.      The  -white  oxide  of  zinc  is  much  used  for  white  paint  in  place  of  white  lead,  and  also  in  making  a  glass  for  optical  purposes. 


Dissolves  in  nitric  acid, 
emitting  sulphuretted 
hydrogen.  Soluble 
also  in  HC1. 


Brown,    yel-     Resin-         Brown-     Infus.      3.5-4           4              I.                              See 
low  to                 ous  or        ish  to        or 

black, 
sometimes 

waxy          "gJJ         with 
to  ada-                        diffi- 

green,  red,        man-           ^"te 
and  white;        tine.            Trans- 
nearly  col-                             parent 
orless  when                         to 

culty. 

pure. 

trans- 
lucent. 

' 

1{ 

n 

See  under  heading  ZINC,  etc. 


NAME. 


COMP.  AND 

PERCENTAGE 
OF  IMPORTANT 
CONSTITUENT. 


GENERAL  CHARACTERS  AND  ASSOCIATIONS. 


ZINC  AND  ITS  COMPOUNDS.-Continued. 


SPECIFIC 


BEFORE  BLOWPIPE. 


Zinc 
Carbon- 
ate 

(Smith- 
sonite; 
"Dry- 
bone  "). 


Zinc 
Silicate 
(Cala- 
mine; 
Electric 
Gala- 
mine). 


ZnCO,. 
Fe,  Mn, 
Ca,  and 
Mg  often 
present. 

Zinc,  52*. 


ZnaSiO4 
+  H20. 

Zinc,  54.2*. 


Crystals  over  drusy  surface  usually  terminate  in  sharp  three-sided 
pyramids.  Faces  of  crystals  generally  rough  and  curved. 
Reniform,  botryoidal,  or  stalactitic  and  incrusting.  Roughly 
friable  and  sometimes  earthy.  Usually  rough  and  granular. 
Markedly  harsh  to  feel.  Brittle.  Cleavage  perfect,  but  frac- 
ture uneven.  Found  in  veins,  but  more  usually  in  irregular 
deposits  in  limestone  strata.  Usually  produced  by  action  upon 
zinc  sulphide  of  carbonated  waters,  and  is  therefore  nearly 
always  an  alteration  product  of  the  originally  deposited  ore. 
Associated  with  blende,  calamine,  galena,  and  with  limonite 
and  copper  ores.  An  earthy  variety  is  zinc-bloom,  (hydrozincite). 


Infusible  alone,  but  CO2  and  zinc 
oxide  are  finally  vaporized  with 
i-oda  on  charcoal,  producing  coating 
which  can  be  treated  as  above. 


Stalactitic,  matnmillary,  botryoidal,  fibrous,  but  also  massive  and 
granular,  sometimes  cellular.  In  physical  characters  somewhat 
resembles  the  preceding  ore.  An  anhydrous  variety  of  this  ore 
is  luillemite,  which  is  found  with  the  two  following  ores  in  New 
Jersey  (Mine  Hill  and  Sterling  Hill). 

Like  the  former,  it  is  usually  found  in  veins,  or  in  beds,  or  in 
irregular  pockets  in  stratified  calcareous  rocks,  in  association 
with  zinc-blende,  zinc  carbonate,  iron  and  lead  ores,  etc. 


The  smallest  fragment  heated  at- 
tracts light  substances.  Pyro-elec- 
tric.  Almost  infusible.  Moistened 
with  cobalt  solution  gives  a  blue 
color  when  heated. 


152 


CHARACTERS. 

COLOR. 

LUSTRE. 

STREAK 

FUSI- 
BILITY. 

I 

HARD-       s     G 

NESS.             SP<  ^R< 

CRYS- 

TALLI- 

MAGNHTIC 
BEFORK                                   USES 

OR  AFTER                                                   U!>Bb. 

TREATMENT  WITH  ACIDS.KTC, 

[|||    **»»"•  j   HEATING.  | 

] 

Gives  little  or  no  water 

Impure 

Vitre- 

Un-        Infus.          5            4.4          III.                          See  under  heading  ZINC,  etc. 

in  closed    tube.     Dis- 

white to 

ous, 

col- 

solves  in    HC1,    with 

grayish, 

pearly. 

ored 

• 

evolution  of  carbonic 

sometimes 

Sub- 

or 

. 

acid,    causing     effer- 

green or 

trans- 

white. 

vescence. 

brownish 

parent 

and  other 

to 

tinges. 

trans- 

lucent. 

Gives   much    water   in 
closed      tube.       With 

Whitish  or 
white, 

Vitre- 
ous or 

Un-             6          4.5-5         3.5          IV. 
col- 

See under  heading  ZINC,  etc. 

HC1   forms  a  perfect 

sometimes 

sub- 

ored 

jelly  even  when   pre- 

with 

pearly 

or 

viously  ignited.     De- 

bluish- 

to  ada- 

white. 

composed     by    acetic 

green  or 

man- 

acid   and    soluble    in 

brownish 

tine. 

strong      solution      of 

tinges. 

caustic  potash. 

Also 

yellowish 

to  brown. 

1 

53 

NAME. 


COMP.  AND 
PERCENTAGE 
OP  IMPORTANT 
CONSTITUENT. 


GENERAL  CHARACTERS  AND  ASSOCIATIONS. 


ZINC  AND  ITS  COMPOUNDS.— Continued. 


SPECIFIC 


BEFORE  BLOWPIPE. 


Red  Ox- 
ide of 
Zinc 
(Zincite; 
Ruby 
Zinc). 

Frank- 
linite. 


ZnO*MnO 
is  fre- 
quently 
present. 

Zinc,  80.  3£. 


Distinguished   by  its   eminent   cleavage,  infusibility,   and  by  its     Infusible  alone,  but  yields  a  yellow 


mineral  associations.     It  is  brittle  and  has  subconchoidal  frac- 
ture.     On  exposure   to  the  air  it  decomposes  superficially   and 
becomes  coated  with  white  films  of  zinc  carbonate. 
Occurs  with  franklinite  and  willemite  in  New  Jersey,  and  some- 
times  in  lamellar  masses  in  pink  calcite. 


transparent  glass  with  borax.  If 
manganese  be  present,  the  bead  is 
amethystine.  Zinc  coating  on  coal 
when  treated  with  soda  in  R.  F. 


(Fe,Zn,Mn)  See  Iron  Ores,  among  which  it  is  enumerated,  although  it  is  a  very  important  zinc  ore  and  is  extensively 

O.(Fe,Mn)»  Hill  and   Mine   Hill,   N.   J.     Usually  contains  about   ioj{  zinc,   the   residuum,  known  as  "  clinker," 

O3.     Vari-  manufacturers  of  spiegeleisen. 

able. 


Zinc, 


j 


12*  (?). 


Zircon.         ZrSiO4. 


A  somewhat  rare  mineral.  Generally  in  crystals  (square  four- 
sided  prisms  terminated  by  four-sided  pyramids);  also  in  grains, 
etc.  Brittle.  Conchoidal  fracture. 

Confined  to  crystalline  rocks,  usually  occurring  in  granite,  syenite, 
some  of  the  gneisses,  granular  limestone,  chloritic  and  other 
schists,  and  in  some  igneous  rocks.  Sometimes  it  is  found  in 
iron-ore  beds;  is  also  found  in  alluvial  deposits  associated  with 
precious  stones  and  gold. 


Becomes  colorless  upon  heating.  In 
powder  is  decomposed  when  fused 
with  soda  on  platinum  wire. 


154 


CHARACTERS. 

pcv<          MAGNETIC 

COLOP                LUSTRE        STREAK                         WARD-      gp    ^^        TALLI-                                                         USES 

TREATMENT  WITH  ACIDS,  ETC. 

ESS                                        ZATION.          H^ATH«f 

Heated  in  closed  tube 
blackens,  but  resumes 

Deep  red  to      Subada-     Orange     Infus.      4-4.  5         5-6          III. 
orange-              man-          yellow. 

See  under  heading  ZINC,  etc. 

its    original  color    on 

yellow.               tine. 

cooling.       Soluble    in 

acids     without    effer- 

vescence. 

• 

mined  in  New  Jersey  fo 

r  the  extraction  of  this  metal.    Occurs  with  willemite  and  zincite  at  Sterling     See  under  heading  ZINC,  etc. 

remaining  after  the  e 

straction  of 

the   zinc,  being   treat 

ed  as  a 

i  manga 

nese  on 

•  and   so 

Id   to  the 

Fused  with    soda,  and 

Red,  brown,     Ada- 

Un- 

Infus. 

7-5 

4-5 

II. 

Used    to   a   small   extent   in 

the    fusion    dissolved 

yellow,               man-           col- 

jewelling  watches. 

in  HC1,  the  dilute  acid 

green,  or           tine.            ored. 

solution     turns      tur- 

gray; pale 

meric    paper    orange- 

yellowish 

yellow  (zirconia).   Not 

to 

acted    upon   by   acids 

colorless. 

except  in  fine  powder 

> 

with  concentrated  sul- 

phuric acid 

155 


II.-CLASSIFICATION  OF  MINERALS. 

(AFTER   BRUSH.) 

MINERALS  WITH  METALLIC  LUSTRE. 

A. — Fusible  from  1-5,  or  easily  volatile  : — Native  antimony — stibnite — native  arsenic — arsenopyrite — bismuth — bismuth  planet 
—  tetradymite  —  wittichite  —  smaltitt — cobalt  glance — linnceitt — native  copper — copper  pyrites — chalcocite — bornite — tetrahedrite — native 
gold — sylvanite — nagyagite — magnetite — hematite  {specular  iron) — iron  pyrites — marcasite — pyrrhotite  — galena — native  mercury-cin- 
naoar  —  niccolite  — pentlandite  —  millerite — ullmannite — gersdorjfite — platinum — silver — argentite — stephanite — dyscrasite — miargyrite — 
polybasite — freieslebenite — stromeyerite — stannite — wolframite. 

B. — Infusible  or  fusible  above  5,  and  non-volatile  : — Chromite — graphite — iridosmine — magnetite — hematite  (specular  iron) — 
turgite — limonite — ilmenite — franklinite — pyrolusite — psilomelane — braunite — manganite — hausmannite — molybdenite. 

MINERALS  WITHOUT  METALLIC  LUSTRE. 

A. — Easily  volatile,  or  combustible  B.  B. : — Valentinite — kermesite — orpiment — realgar — cinnabar— calomel — sulphur, 

B. — Fusible   1-5,  and   non-volatile,  or  only   partially  volatile.     (I)  Those   which   yield  a  metal  or  magnetic  mass  with 

soda  . Bismutite  —  crocoite  —  cobalt  bloom — malachite — azurite — atacamite — cuprite — almandite — iron    lime  garnet — hematite — siderite 

cerussite  —  rhodonite  —  wulfenite  —  annabergite  — pyrargyrite  — prousiite  —  cerargyrite — embolite — bromyrite — iodyrite — wolframite— 

hubnerite. 

156 


(II)  Those  which  do  not  yield  a  metal  or  magnetic  mass  with  soda  : — Cryolite— potash  atum  (kalinite) — apatite — asbestos 
{amianthus,  actinolite]  —  barite  —  borax  —  gypsum — epidote — orthoclase — oligoclase — albite — fluor-spar — halite — hornblende  (amphibole} — 
rhodonite — nitre  (common  saltpetre,  Chile  saltpetre) — obsidian — pyroxene — scheelite — wollastonite, 

C. — Infusible,  or  fusible  above  5  : — Bauxite — cer-vantite — apatite — asbestos  (chrysotile  or  bostonite) — calcite  (limestone} — dolo- 
mite— asbolite — chrysocolla — corttndum — diamond — emerald— fire-clay — chrome  garnet — turgice—*  limonite — bog  iron  ore — siderite — ankerite 
— kaolinite — chlorite — serpentine — talc — magnesite — wad — rhodochrosite — mica  (muscovite) — monazite — gent  kite — zaratite  —  opal — hyper- 
sthene — ruby — rutile — sapphire — quartz — cassiterite — scheelite — turquois — sphalerite — smithsonite  —  zinc-bloom  —  calami  ne  —  willemite — 
zincite — zircon. 

Hydrocarbons  : — Anthracite — bituminous  coal — lignite — asphalt. 


III.— APPENDIX. 

TEST  FOB  ALL  CARBONATES  (Calcite,  Dolomite,  Malachite,  Siderite,  Cerussite,  etc.). 

Make  a  bead  of  salt  of  phosphorus,  and  heat  in  O.  F.  until  all  bubbles  are  out.  Then  take  up  a  minute  fragment  of  the 
mineral  to  be  tested  in  the  bead  and  heat  in  O.  F.  If  the  fragment  gives  off  gas  or  effervesces  in  the  bead,  causing  bubbling  in 
the  bead,  it  is  a  carbonate.  The  usual  effervescence  with  hydrochloric  and  nitric  acids  is  a  further  test. 

TEST  FOR  SILICA  AND  SILICATES. 

The  substance  to  be  tested  is  broken,  and  a  fragment  heated  for  three  minutes  in  the  O.  F.  in  a  bead  of  salt  of  phosphorus, 
as  for  carbonates.  Silica  and  most  silicates  give  a  skeleton  of  undissolved  silica,  which  remains  in  the  bead.  Metallic  oxides  and 
other  salts  are  dissolved,  leaving  no  skeleton.  Some  silicates  do  not  give  this  reaction,  but  quartz  always  gives  it. 

TEST  BY  HEATING  WITH  COBALT  NITRATE. 

The  mineral  is  ignited  strongly  in  the  O.  F.  and  then  moistened  with  a  drop  of  cobalt  nitrate  and  again  ignited.  The 
fragment  may  be  supported  on  charcoal  or  in  the  platinum  forceps. 

ALUMINA  gives  a  blue  color  (clay,  etc.,  same). 

MAGNESIA  gives  a  pink  color. 

ZINC  AND  TIN  (see  description).  The  coating  on  charcoal  produced  by  burning  zinc  when  moistened  with  cobalt  nitrate 
gives  a  yellow  or  dirty-green  color.  The  coating  on  charcoal  produced  by  burning  tin  when  so  moistened  gives  a  bluish-green 
color. 

SILICA  gives  a  faint  bluish  color.     Generally  partially  fused. 

Note. — All  minerals  assuming  a  dark  color  on  heating,  or  remaining  dark  on  heating,  cannot  be  used  in  this  test. 

158 


TEST   BY  FLAME   COLORS. 

A  long  colorless  O.  F.  is  blown.     A  fragment  of  the  substance  is  then  approached  to  the  flame  (being  held  in  platinun 
forceps).     When  it  touches  the  flame  just  back  of  the  inner  blue  point,  the  color  imparted  to  the  flame  beyond  this  is  to  be  noted. 
CALCIUM  gives  a  reddish-orange  color  (calcite,  dolomite,  etc.). 
BARIUM  gives  a  yellowish-green  color  (barite,  witherite,  psilomelane,  etc.). 
STRONTIUM  gives  a  scarlet  color  (celestite,  strontianite,  etc.). 
SODIUM  gives  an  intense  orange-yellow  color  (feldspar,  Chile  nitre,  etc.). 
POTASSIUM  gives   a  violet  or  lavender  color  (feldspar,  etc.;  also  common  nitre). 
LITHIUM  (rare)  gives  a  deep-red  color,  with  tinge  of  purple  (lepidolite,  etc.). 

A  FEW  SIMPLE  TESTS. 

A. — Lead.  If  the  specimen  is  very  heavy,  and  on  cutting  shows  a  surface  having  a  grayish  metallic  appearance,  it  may 
be  galena  or  lead  sulphide.  If  it  is  heavy,  with  no  metallic  shine,  and  of  a  yellowish  color,  it  may  be  carbonate  of  lead.  In 
either  case  put  a  few  drops  of  nitric  acid  on  the  rock,  then  after  a  minute  as  much  water,  and  finally  place  a  small  piece  of 
iodide  of  potash  on  the  wet  spot.  If  the  rock  turns  a  bright  yellow,  lead  is  present,  etc. 

B. — Copper.  Specimens  having  a  strong  blue  or  green  color,  or  with  a  gray  metallic  lustre,  and  hard  to  cut,  should  be 
tested  for  copper.  Treat  with  nitric  acid,  as  before;  then  add  quite  a  little  ammonia-water;  if  the  sample  turns  a  very  deep  blue, 
copper  in  some  form  is  in  the  ore.  (Do  not  confound  with  nickel.) 

C. — Silver.  For  silver,  grind  a  small  fragment  to  a  fine  powder;  put  one  half  in  a  small  bottle  with  a  little  strong  ammonia- 
water;  shake,  cork,  and  let  stand  for  some  hours;  pour  off  the  solution,  and  add  an  equal  quantity  of  nitric  acid.  If  the  liquid 
becomes  milky,  or  a  curdy  mass  forms  in  it,  there  is  chloride  of  silver  in  the  ore.  The  other  half  is  to  be  heated  in  a  test-tube 
with  nitric  acid,  the  solution  poured  off,  and  a  grain  or  two  of  common  table  salt  added.  If  a  curdy  mass  forms  which  does  not 
dissolve  in  boiling  water  (but  does  dissolve  in  ammonia)  and  turns  dark  on  exposure  to  light,  silver  is  present. 

D. — Gold.     Gold  can  be  proven  with  certainty  only  by  "  panning"  or  assaying.     (W.  L.  Brown.) 

159 


PROCESS  OP  ASSAYING  FOR  SILVER  AND  GOLD. 

(A)  By  the  Scarification  Method. 

In  brief  :  Grind  ore  in  mortar  very  fine,  so  that  it  will  pass  through  an  8o-mesh  sieve,  and  weigh  one  tenth  of  an  assay  ton  of 
it.  Next  weigh  about  one  assay  ton  of  test  lead  and  divide  in  halves;  put  one  half  in  a  scorifier  and  mix  with  it  the  ore;  place  the 
other  half  on  top,  and  add  a  piece  of  borax  glass  the  size  of  a  pea;  heat  in  a  furnace  in  a  muffle  till  everything  in  the  scorifier  is 
melted  and  no  vapors  of  lead  arise  from  it.  Take  out,  pour  in  an  iron  mould,  break  slag  from  button  with  a  hammer,  place  button 
in  a  cupel  in  the  muffle,  and  heat  until  the  lead  has  been  driven  off;  weigh  in  milligrammes  bead  left  in  cupel,  which  bead  equals 
gold  and  silver.  Place  this  bead  in  a  test-tube  and  heat  with  nitric  acid  to  dissolve  the  silver;  pour  off  acid  and  wash  with  dis- 
tilled water,  take  out  the  gold,  dry  and  weigh;  first  weight  less  second,  equals  silver;  each  result  multiplied  by  ten,  equals  the 
number  of  ounces  troy  per  ton  avoirdupois  of  the  precious  metal  contained  in  the  ore.  Often  advisable  to  unite  a  number  of 
buttons  when  separating  the  gold  from  the  silver. 

(B)  By  the  Crucible  Method. 

Used  where  the  character  of  the  ore  is  well  known  and  flux  prepared  accordingly.  Weigh  one-half  an  assay  ton  of  the 
pulverized  ore,  add  requisite  amount  of  flux  (50  to  80  gms.),  cover  with  borax  glass,  fuse  in  muffle  from  twenty  to  forty  minutes, 
pour  in  mould,  and  proceed  exactly  as  in  the  scorification  method  except  as  to  multiplying  the  weights  by  two  instead  of  by  ten. 

ASSAYS  OP  SILVER  ORES.— B.  B. 

An  amount  equal  to  100  mgm.  of  the  ore  is  weighed  out,  and  mixed  with  500  mgm.  test-lead,  and  one  spoon  (about  100 
mgm.)  borax  glass,  the  mixing  being  done  in  the  brass  scoop.  Make  a  cartridge  of  soda-paper  (this  is  filter-paper  soaked  in  soda 
solution  and  then  dried),  place  the  mixture  in  the  cartridge,  and  fold  up  tight.  Then  put  the  cartridge  in  the  charcoal  crucible 
and  heat  in  a  good  reducing  flame  until  all  the  paper  is  charred.  Keep  covered  by  the  reducing  flame  until  all  paper  is  burned 
and  the  lead  is  in  one  button  and  the  slag  in  another.  Then  oxidize  in  O.  F.  until  the  lead  button  is  yellowish  on  cooling,  and  red 
when  hot.  (As  long  as  the  sulphur  remains  in  the  button  it  will  be  dark  gray  or  black  on  cooling,  not  yellow.)  When  the  button 
is  yellow  when  cool,  pour  out  on  the  anvil,  make  a  cupel,  and  heat  it  to  expel  moisture;  then  place  the  button  on  the  cupel  and  heat 
until  it  has  been  reduced  to  one-tenth  inch  in  diameter.  Allow  the  litharge  formed  to  collect  around  the  button;  conduct  this  part 

160 


of  the  operation  at  a  low  temperature.  Now  make  another  cupel;  prepare  the  surface  by  oxidizing  a  little  test-lead  and  driving 
the  oxide  into  the  cupel;  place  the  button  broken  from  the  former  cupel  on  this  newly-prepared  one  and  complete  the  cupellation. 
In  this  last  operation  direct  the  flame  (hot  O.  F.)  at  the  cupel  around  the  button  rather  than  at  the  button  itself,  and  do  not  allow 
the  bottom  of  the  cupel  to  become  "wet,"  i.e.,  keep  all  the  litharge  soaked  up  by  the  cupel.  As  the  button  nears  the  glance, 
white  specks  appear  on  its  surface,  then  a  play  of  prismatic  colors,  then  for  a  moment  it  is  dull,  and  suddenly  it  breaks  out  in  a 
bright  glow,  which  almost  immediately  fades.  This  last  is  the  glance;  when  it  fades  the  cupellation  is  complete;  stop  blowing. 
Weigh  in  mgms.;  this  gives  percentage,  i  per  cent,  or  each  milligramme  =  291.66  oz.  per  ton. 

In  case  of  poor  ores  cupel  several  portions  of  100  mgm.  down  to  one-tenth  inch  as  above,  and  then  unite  these  buttons 
and  cupel  to  a  finish.  The  final  button  may  be  weighed,  or  if  less  than  i  mgm.  it  may  be  measured  on  the  Plattner  scale,  and 
the  weight  thus  ascertained. 

ASSAYS  OP  MERCURY  ORES. 

Mix  500-1000  mgms.  in  fine  powder  with  5-10 gms.  litharge  and  introduce  into  a  tube,  bent  with  an  ejbow.  This  glass  tube 
is  one-fifth  inch  in  diameter  and  seven  to  eight  inches  long.  Heat  until  the  assay  is  fused  and  the  glass  becomes  attacked.  Mer- 
cury collects  beyond  the  elbow  in  drops;  condense  the  deposits  there  by  careful  heating;  break  the  tube  and  weigh  portion  with 
mercury.  Then  clean  out  mercury  and  weigh  again;  difference  is  mercury;  0.05  per  cent  may  be  thus  estimated. 

TO  OBTAIN  PERCENTAGE  OF  A  GIVEN  ELEMENT  IN  AN  ORE. 

To  get  the  percentage  of  any  element  in  a  given  ore  or  compound  is  simply  a  matter  of  proportion — e.g.,  Magnetic  Iron 
Ore  (FesO4).  First  refer  to  tables  of  atomic  weights,  and  we  find  the  atomic  weight  of  iron  (Fe)  to  be  56,  which  multiplied  by  3 
gives  168;  while  the  atomic  weight  of  oxygen  (O)  is  16,  which  multiplied  by  4  gives  64.  These  added  (168  +  64)  give  232.  Now 
make  the  proportion  232  :  100  ::  168  :  x,  and  it  is  found  that  72.4  is  the  percentage  of  metallic  iron.  In  the  same  way  the  percentage 
of  oxygen  is  found  to  be  27.5.  The  method  shown  in  the  above  example  gives  the  possible  percentage  in  any  ore  or  compound 
according  to  the  chemical  formulae  given  in  the  "  Tables."  Such  purity  as  is  indicated  by  the  formulae  is,  however,  very  rarely 
and  in  many  cases  never  met  with.  It  follows,  of  course,  that  the  percentage  of  the  desirable  element  in  the  ore  is  reduced  in 
proportion  to  the  impurities  present. 


(*-«       ,n) 

X.v.3h^o          ,/ 


IV.-INDEX  TO  TABLES. 


Actinolite 30,  74 

Albertite 74 

Albite. 64 

Almandite 67 

Alum 22 

Aluminum ,. .     20 

Amethyst 60,  132 

Amianthus 30 

Ammonia  Alum 22 

Amphibole 74 

Anhydrite. 42 

Anthracite 46 

Ankerite 92 

Annabergite 122 

Antimony 22 

Antimony  Glance 24 

Apatite 26 

Aragonite 42 

Argentiferous  Cerussite 140 

Argentiferous  Galena 140 


Argentiferous  Pyrites 140 

Argentiferous  Zinc  Blende 140 

Argentite 134 

Argillaceous  Hematite 88 

Arsenic 28 

Arsenopyrite 28 

Asbestos 30,  74 

Asbestus 30 

Asbolite 52 

Asphalt 78 

Atacamite , . . .  58 

Auriferous  Iron  Pyrites 70 

Auriferous  Galena ?r 

Auriferous  Zinc  Blende 71 

Augite  (Green) ... 128 

Augite  (White) .  128 

Aventurine  Feldspar 65 

Azurite 56 

Barite 32 

163 


I'AGE 

Bauxite 20 

Bell  Metal  Ore 144 

Beryl , 62 

Bismutite 36 

Bismuth 32,  34 

Bismuth  Glance 34 

Bismuthinite 34 

Bismuth  Ochre 36 

Bismuth  Sulphide 34 

Bituminous  Coal . 48 

Bitumen 78 

Black  Band  Ore 92 

Black  Copper  Ore 58 

Black  Copper  Sulphide 54 

Black  Jack 150 

Blue  Malachite 56 

Bog  Iron  Ore 90 

Bog  Manganese iof> 

Borate  of  Soda 36 

Borax 36 


INDEX  TO  TABLES.-Continued. 


PAGE 

Bornite 56 

Bostonite 100 

Braunite. . . . 106 

Brittle  Silver 134 

Bromyrite 140 

Bronzite 128 

Brown  Coal 48 

Brown  Hematite 90 

Calamine 152 

Calaverite 70 

Calcareous  Sinter 38 

Calcite  (Calcium  Carbonate) 38 

Calcium 38 

Calc  Spar 38 

Caliche 122 

Calomel no 

Cannel   Coal 48 

Capillary  Pyrites 120 

Carbuncle 67 

Cassiterite 144 

Celestite 42 

Cerargyrite 138 

Cerussite .......     98 

Cervantite. 24 


Chalcedony 133 

Chalcocite 54 

Chalcopyrite 54 

Chile  Saltpetre 122 

China-clay 96 

Chloanthite 50,  116 

Chloride  of  Silver 58 

Chlorine 44 

Chlorites 100 

Chromate  of  Lead 46 

Chromite  (Chromic  Iron) 44 

Chromium 44 

Chrysocolla 58 

Chrysotile 30,  100 

Cinnabar no 

Clay 64 

Clay-ironstone 92 

Coals 46 

Cobalt 50 

Cobalt  Bloom 52 

Cobaltite  (Cobalt  Glance) 50 

Cobalt  Pyrites 52 

Cockscomb  Pyrites 94 

Coke  (Coking  Coal) 46,  48,  49 

Coloradoite 112 

104 


Copper 54 

Copper  Carbonate 56 

Copper  Glance 54 

Copper  Nickel 116 

Copper  Pyrites 54 

Copper  Silicate 58 

Copper  Sulphide 54 

Corundum 60 

Crocoite 46 

Cryolite 20 

Cu  prite 58 

Dark-red  Silver  Ore 136 

Diallage j 28 

Diallogite 108 

Diamond 62 

Dolomite 40 

Dry  Bone 152 

Dyscrasite 134 

Earthy  Cobalt 52 

Electric  Calamine 152 

Electro-silicon 81 

Embolite 138 

Emerald ....  62 


INDEX  TO  TABLES.-Continued. 


PAGE 

Emerald  Nickel 118 

Emery 60 

Epidote 62 

Epsom  Salts 103 

Erubescite 56 

Erythrite 52 

Feldspar 64 

Fire-clay 64 

Fire  Opal 124 

Flos-ferri 42 

Fluorite 66 

Fluor-spar 66 

Fossil  Iron  Ore 88 

Franklinite 96,  154 

Freieslebenite 136 

Fuller's  Earth 66 

Galena  (Galenite) 98 

Garnet 66 

Garnierite 118 

Genthite 118 

German  Silver 116 

Gersdorffite 120 

Gilsonite 76 


PACK 

Goethite 88 

Gold 68 

Grahamite 76 

Graphite 72 

Gray  Copper 60 

Gypsum 40 

Halite 72 

Halotrichite 22 

Hauntajayite 138 

Hausmannite 106 

Heavy  Spar » 32 

Hematite 84 

Hornblende 74 

Horn  Silver 138 

Hubnerite 146 

Hydraulic  Limestone 40 

Hydrocarbons 74 

Hydrozincite 152 

Hypersthene 128 

I  Imeni  te 94 

Infusorial  Earth 80 

Iodine 122 

lodyrite 140 

165 


Iridium. 82 

Iridosmine 82 

Iron 82 

Iron  Carbonate 92 

Iron  Pyrites 94 

Iron  Sulphide 94 

Iserine 94 

Isinglass 112 

Itabiryte 86 

Jasper 133 

Jaspery  Clay  Iron-stone 88 

Jet 48 

Kalinite .-- 22 

Kaolin 96 

Kaolinite 96 

Kermesite 24,  26 

Kidney  Ore 84 

Lead 98 

Lead  Carbonate 98 

Lead  Sulphide 98 

Lenticular  Iron  Ore 88 

Light-red  Silver  Ore 136 

Lignite 48 


INDEX  TO  TABLES.-Continued. 


Limestone 38 

Limonite 90 

Linnaeite 52 

Lithographic  Stone 39 

Magnesite 102 

Magnesium 100 

Magnetic  Iron  Pyrites 96 

Magnetic  Iron  Ore 84 

Magnetite 84 

Malachite 56 

Maltha 78 

Manganese 104 

Manganese  Carbonate 108 

Manganese  Silicate. 108 

Manganese  Spar 108 

Manganite 106 

Marble 38 

Marcasite 94 

Martite 86 

Melaconite 58 

Menaccanite 94 

Mendozite 22 

Mercury 108,  no 

Mercury  Chloride , .  no 


Mercury  Telluride 112 

Mexican  Onyx. 38,  132 

Miargyrite 134 

Mica 112 

Micaceous  Iron  Ore 86 

Millerite 120 

Mineral  Oil 78 

Mineral  Tar 78 

Mispickel 28 

Molybdate  of  Lead 114 

Molybdenite 114 

Molybdenum 114 

Monazite 114 

Moon  Stone 65 

Mountain  Cork 30,  74 

Mountain  Leather 30,  74 

Mountain  Paper 74 

Mountain  Wood 74 

Muscovite 112 

Nagyagite 70 

Natural  Gas 80 

Niccolite 1 16 

Nickel 116 

Nickel  Arsenic 122 

166 


Nickel  Blende  ......................  120 

Nickel  Carbonate  ..................  118 

Nickel  Glance  ......................  120 

Nickeliferous  Iron  Pyrites  ..........  120 

Nickel  Ochre  .......................  122 

Nickel  Silver  .......................  116 

Nickel  Sulphide  ....................  120 

Nitre  ..............................  122 

Nitric  Acid  .........................  123 

Noumeite  ..........................  nS 

Obsidian  ...........................  124 

Odontolite  .........................  U9 

Oligoclase  ....................  •  .....  64 

Onyx  ............................  38,  132 

Opal  ...  .....................  •  ......  I2-* 

Oriental  Amethyst  .................  6° 

Oriental  Emerald.  .  .................  62 

Orpiment  .......................... 

Orthoclase  .........................  64 

Ozokerite  ......................  •  -  •  •  76 


Peach-blossom  Ore 
Peacock  Ore 
Pentlandite 


52 


INDEX  TO  TABLES.-Continued. 


Petroleum 78 

Pitt  Asphalt 78 

Phosphate  Rock 26,  27,  126 

Phosphorite 26 

Plaster  of  Paris 40,  41 

Platinum 126 

Polybasite 136 

Potash  Alum 22 

Potash  Nitre. 122 

Potstone 102 

Proustite 136 

Psilomelane 104 

Pumice 124 

Pyrargyrite 136 

Pyrites 94 

Pyrolusite 104 

Pyroxene 128 

Pyrrhotite 96 

Quartz 132 

Realgar 30 

Red  Copper  Oxide 58 

Red  Ochre 88 

Red  Oxide  of  Zinc 154 


PAGE 

Red  Shale  Ore 88 

Rhodochrosite 108 

Rhodonite '.' 108 

Rock  Salt 72 

Ruby 130 

Ruby  Zinc 154 

Rutile 130 

Salt 72 

Saltpetre 122 

Sapphire 130 

Scheelite 148 

Semi-bituminous  Coal 48 

Serpentine 30,  100 

Siderite 92 

Silex 81 

Silica  132 

Silicified  Wood 133 

Silver 132 

Silver  Chloride 138 

Silver  Copper  Glance 136 

Silver  Glance 134 

Silver  Sulphide 134 

Smaltite 50 

Smithsonite 152 

167 


PAGE 

Soapstone 102 

Soda  Alum 22 

Soda  Nitre 122 

Soft  Hematite 86 

Spathic  Iron  Ore. 92 

Specular  Iron  Ore 86 

Speiss  Cobalt 50 

Sperrylite 120,  128 

Sphalerite > 150 

Stalactite 38 

Stalagmite 38 

Stannite 144 

Steatite 102 

Stephanite 134 

Stibnite 24 

Stream  Tin 144 

Stromeyerite 136 

Sulphur 142 

Sun  Stone 65 

Sylvanite 70 

Tabular  Spar 150 

Talc 102 

Telluride  of  Gold 70 

Tellurium 142 


INDEX  TO  TABLES.-Continued. 


Tennantite 60 

Tetradymite 36 

Tetrahedrite 60,  140 

Thorium  Sands 114 

Tin 144 

Tincal 36 

Tin  Pyrites 144 

Tin  Stone 144 

Tin  Sulphide 144 

Topaz 146 

Travertine 38 

Tremolite •  74 

Tripolite 80 

Tungsten 148 

Turgite 88 


Turquois. 


PAGE 
148 


Uintahite 76 

Ullmannite 120 

Valentinite 24 

Variegated  Copper  Pyrites 56 

Velvet  Iron  Ore 88 

Volcanic  Glass 124 

Vulpinite 43 

Wad 106 

White  Antimony 24 

White  Iron  Pyrites 94 

Willemite 152 

Wittichite 36 


Wolframite 146 

Wollastonite 150 

Wulfenite 114 

Yellow  Ochre 90 

Zaratite 118 

Zinc 150 

Zinc  Blende 150 

Zinc  Bloom 152 

Zinc  Carbonate 152 

Zincite 1 54 

Zinc  Silicate 152 

Zinc  Sulphide 150 

Zircon 154 


168 


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